1663 | Smallest String With A Given Numeric Value | Solution | | Medium | Greedy |
1662 | Check If Two String Arrays are Equivalent | Solution | | Easy | String |
1658 | Minimum Operations to Reduce X to Zero | Javascript | | Medium | Greedy |
1657 | Determine if Two Strings Are Close | Solution | | Medium | Greedy |
1656 | Design an Ordered Stream | Solution | | Easy | Array, Design |
1652 | Defuse the Bomb | Solution | | Easy | Array |
1646 | Get Maximum in Generated Array | Solution | | Easy | Array |
1640 | Check Array Formation Through Concatenation | Solution | | Easy | Array, Sort |
1637 | Widest Vertical Area Between Two Points Containing No Points | Javascript | | Medium | Sort |
1636 | Sort Array by Increasing Frequency | Solution | | Easy | Array, Sort |
1630 | Arithmetic Subarrays | Solution | | Medium | Sort |
1629 | Slowest Key | Solution | | Easy | Array |
1626 | Best Team With No Conflicts | Solution | | Medium | DP |
1625 | Lexicographically Smallest String After Applying Operations | Solution | | Medium | BFS, DFS |
1624 | Largest Substring Between Two Equal Characters | Solution | | Easy | String |
1620 | Coordinate With Maximum Network Quality | Solution | | Medium | Greedy |
1619 | Mean of Array After Removing Some Elements | Solution | | Easy | Array |
1614 | Maximum Nesting Depth of the Parentheses | Solution | | Easy | String |
1609 | Even Odd Tree | Solution | | Medium | Tree |
1608 | Special Array With X Elements Greater Than or Equal X | Solution | | Easy | Array |
1604 | Alert Using Same Key-Card Three or More Times in a One Hour Period | Solution | | Medium | String, Ordered Map |
1603 | Design Parking System | Solution | | Easy | Design |
1601 | Maximum Number of Achievable Transfer Requests | Solution | | Hard | Backtracking |
1598 | Crawler Log Folder | Solution | | Easy | Stack |
1592 | Rearrange Spaces Between Words | Solution | | Easy | String |
1588 | Sum of All Odd Length Subarrays | Solution | | Easy | Array |
1583 | Count Unhappy Friends | Solution | | Medium | Array |
1582 | Special Positions in a Binary Matrix | Solution | | Easy | Array |
1576 | Replace All ?'s to Avoid Consecutive Repeating Characters | Solution | 📺 | Easy | String |
1574 | Shortest Subarray to be Removed to Make Array Sorted | Solution | | Medium | Array, Binary Search |
1572 | Matrix Diagonal Sum | Solution | | Easy | Array |
1570 | Dot Product of Two Sparse Vectors | Solution | | Easy | Array, HashTable, Two Pointers |
1567 | Maximum Length of Subarray With Positive Product | Solution | 📺 | Medium | Greedy |
1566 | Detect Pattern of Length M Repeated K or More Times | Solution | 📺 | Easy | Array |
1561 | Maximum Number of Coins You Can Get | Solution | 📺 | Medium | Sort |
1560 | Most Visited Sector in a Circular Track | Solution | | Easy | Array |
1558 | Minimum Numbers of Function Calls to Make Target Array | Solution | | Medium | Greedy |
1557 | Minimum Number of Vertices to Reach All Nodes | Solution | 📺 | Medium | Graph |
1556 | Thousand Separator | Solution | 📺 | Easy | String |
1551 | Minimum Operations to Make Array Equal | Solution | 📺 | Medium | Math |
1550 | Three Consecutive Odds | Solution | | Easy | Array |
1545 | Find Kth Bit in Nth Binary String | Solution | 📺 | Medium | String |
1544 | Make The String Great | Solution | 📺 | Easy | String, Stack |
1541 | Minimum Insertions to Balance a Parentheses String | Solution | 📺 | Medium | String, Stack |
1539 | Kth Missing Positive Number | Solution | 📺 | Easy | Array, HashTable |
1535 | Find the Winner of an Array Game | Solution | 📺 | Medium | Array |
1534 | Count Good Triplets | Solution | | Easy | Array |
1528 | Shuffle String | Solution | | Easy | Sort |
1526 | Minimum Number of Increments on Subarrays to Form a Target Array | Solution | | Hard | Segment Tree |
1525 | Number of Good Ways to Split a String | Solution | 📺 | Medium | String, Bit Manipulation |
1524 | Number of Sub-arrays With Odd Sum | Solution | | Medium | Array, Math |
1523 | Count Odd Numbers in an Interval Range | Solution | 📺 | Easy | Math |
1518 | Water Bottles | Solution | | Easy | Greedy |
1514 | Path with Maximum Probability | Solution | | Medium | Graph |
1512 | Number of Good Pairs | Solution | | Easy | Array, HashTable, Math |
1508 | Range Sum of Sorted Subarray Sums | Solution | | Medium | Array, Sort |
1507 | Reformat Date | Solution | | Easy | String |
1502 | Can Make Arithmetic Progression From Sequence | Solution | | Easy | Array, Sort |
1496 | Path Crossing | Solution | | Easy | String |
1493 | Longest Subarray of 1's After Deleting One Element | Solution | 📺 | Medium | Array |
1492 | The kth Factor of n | Solution | | Medium | Math |
1491 | Average Salary Excluding the Minimum and Maximum Salary | Solution | | Easy | Array, Sort |
1490 | Clone N-ary Tree | Solution | | Medium | HashTable, Tree, DFS, BFS |
1487 | Making File Names Unique | Solution | | Medium | HashTable, String |
1486 | XOR Operation in an Array | Solution | | Medium | Array, Bit Manipulation |
1481 | Least Number of Unique Integers after K Removals | Solution | | Medium | Array, Sort |
1480 | Running Sum of 1d Array | Solution,C++ | | Easy | Array |
1476 | Subrectangle Queries | Solution | | Medium | Array |
1475 | Final Prices With a Special Discount in a Shop | Solution | | Easy | Array |
1471 | The k Strongest Values in an Array | Solution | | Medium | Array, Sort |
1470 | Shuffle the Array | Solution,C++ | | Easy | Array |
1469 | Find All The Lonely Nodes | Solution | | Easy | Tree, DFS |
1466 | Reorder Routes to Make All Paths Lead to the City Zero | Solution | | Medium | Tree, DFS |
1464 | Maximum Product of Two Elements in an Array | Solution | | Easy | Array |
1460 | Make Two Arrays Equal by Reversing Sub-arrays | Solution | | Easy | Array |
1457 | Pseudo-Palindromic Paths in a Binary Tree | Solution | | Medium | Bit Manipulation, Tree, DFS |
1456 | Maximum Number of Vowels in a Substring of Given Length | Solution | | Medium | String, Sliding Window |
1455 | Check If a Word Occurs As a Prefix of Any Word in a Sentence | Solution | | Easy | String |
1452 | People Whose List of Favorite Companies Is Not a Subset of Another List | Solution | | Medium | String, Sort |
1451 | Rearrange Words in a Sentence | Solution | | Medium | String, Sort |
1450 | Number of Students Doing Homework at a Given Time | Solution | | Easy | Array |
1448 | Count Good Nodes in Binary Tree | Solution | | Medium | Tree, DFS |
1447 | Simplified Fractions | Solution | | Medium | Math |
1446 | Consecutive Characters | Solution | | Easy | String |
1441 | Build an Array With Stack Operations | Solution | | Easy | Stack |
1437 | Check If All 1's Are at Least Length K Places Away | Solution | | Medium | Array |
1436 | Destination City | Solution | | Easy | String |
1432 | Max Difference You Can Get From Changing an Integer | Solution | | Medium | String |
1431 | Kids With the Greatest Number of Candies | Solution,C++ | | Easy | Array |
1428 | Leftmost Column with at Least a One | Solution | | Medium | Array |
1427 | Perform String Shifts | Solution | | Easy | Array, Math |
1426 | Counting Elements | Solution | | Easy | Array |
1423 | Maximum Points You Can Obtain from Cards | Solution | | Medium | Array, DP, Sliding Window |
1422 | Maximum Score After Splitting a String | Solution | | Easy | String |
1418 | Display Table of Food Orders in a Restaurant | Solution | | Medium | HashTable |
1417 | Reformat The String | Solution | | Easy | String |
1415 | The k-th Lexicographical String of All Happy Strings of Length n | Solution | | Medium | Backtracking |
1413 | Minimum Value to Get Positive Step by Step Sum | Solution | | Easy | Array |
1410 | HTML Entity Parser | Solution | | Medium | String, Stack |
1409 | Queries on a Permutation With Key | Solution | | Medium | Array |
1408 | String Matching in an Array | Solution | | Easy | String |
1403 | Minimum Subsequence in Non-Increasing Order | Solution | | Easy | Greedy, Sort |
1402 | Reducing Dishes | Solution | | Hard | Dynamic Programming |
1401 | Circle and Rectangle Overlapping | Solution | | Medium | Geometry |
1400 | Construct K Palindrome Strings | Solution | | Medium | Greedy |
1399 | Count Largest Group | Solution | | Easy | Array |
1396 | Design Underground System | Solution | | Medium | Design |
1395 | Count Number of Teams | Solution | | Medium | Array |
1394 | Find Lucky Integer in an Array | Solution | | Easy | Array |
1392 | Longest Happy Prefix | Solution | | Hard | String, Rolling Hash |
1390 | Four Divisors | Solution | | Medium | Math |
1389 | Create Target Array in the Given Order | Solution | | Easy | Array |
1388 | Pizza With 3n Slices | Solution | | Hard | DP |
1387 | Sort Integers by The Power Value | Solution | | Medium | Sort, Graph |
1386 | Cinema Seat Allocation | Solution | | Medium | Array, Greedy |
1385 | Find the Distance Value Between Two Arrays | Solution | | Easy | Array |
1382 | Balance a Binary Search Tree | Solution | | Medium | Binary Search Tree |
1381 | Design a Stack With Increment Operation | Solution | | Medium | Stack, Design |
1380 | Lucky Numbers in a Matrix | Solution | | Easy | Array |
1379 | Find a Corresponding Node of a Binary Tree in a Clone of That Tree | Solution | | Medium | Tree |
1377 | Frog Position After T Seconds | Solution | | Hard | DFS, BFS |
1376 | Time Needed to Inform All Employees | Solution | | Medium | DFS |
1375 | Bulb Switcher III | Solution | | Medium | Array |
1374 | Generate a String With Characters That Have Odd Counts | Solution | | Easy | String |
1373 | Maximum Sum BST in Binary Tree | Solution | | Hard | DP, BST |
1372 | Longest ZigZag Path in a Binary Tree | Solution | | Hard | DP, Tree |
1371 | Find the Longest Substring Containing Vowels in Even Counts | Solution | | Medium | String |
1370 | Increasing Decreasing String | Solution | | Easy | String, Sort |
1367 | Linked List in Binary Tree | Solution | | Medium | DP, Linked List, Tree |
1366 | Rank Teams by Votes | Solution | | Medium | Array, Sort |
1365 | How Many Numbers Are Smaller Than the Current Number | Solution | | Easy | Array, HashTable |
1362 | Closest Divisors | Solution | | Medium | Math |
1361 | Validate Binary Tree Nodes | Solution | | Medium | Graph |
1360 | Number of Days Between Two Dates | Solution | | Easy | |
1358 | Number of Substrings Containing All Three Characters | Solution | | Medium | String |
1357 | Apply Discount Every n Orders | Solution | | Medium | Design |
1356 | Sort Integers by The Number of 1 Bits | Solution | | Easy | Sort, Bit Manipulation |
1354 | Construct Target Array With Multiple Sums | Solution | | Hard | Greedy |
1353 | Maximum Number of Events That Can Be Attended | Solution | | Medium | Greedy, Sort, Segment Tree |
1352 | Product of the Last K Numbers | Solution | | Medium | Array, Design |
1351 | Count Negative Numbers in a Sorted Matrix | Solution | | Easy | Array, Binary Search |
1349 | Maximum Students Taking Exam | Solution | | Hard | Dynamic Programming |
1348 | Tweet Counts Per Frequency | Solution | | Medium | Design |
1347 | Minimum Number of Steps to Make Two Strings Anagram | Solution | | Easy | String |
1346 | Check If N and Its Double Exist | Solution | | Easy | Array |
1345 | Jump Game IV | Solution | | Hard | BFS |
1344 | Angle Between Hands of a Clock | Solution | | Medium | Math |
1343 | Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold | Solution | | Medium | Array |
1342 | Number of Steps to Reduce a Number to Zero | Solution | | Easy | Bit Manipulation |
1341 | The K Weakest Rows in a Matrix | Solution | | Easy | |
1339 | Maximum Product of Splitted Binary Tree | Solution | | Medium | DP, Tree |
1338 | Reduce Array Size to The Half | Solution | | Medium | |
1337 | Remove Palindromic Subsequences | Solution | | Easy | String |
1333 | Filter Restaurants by Vegan-Friendly, Price and Distance | Solution | | Medium | |
1331 | Rank Transform of an Array | Solution | | Easy | |
1329 | Sort the Matrix Diagonally | Solution | | Medium | |
1325 | Delete Leaves With a Given Value | Solution | | Medium | Tree |
1324 | Print Words Vertically | Solution | | Medium | String |
1323 | Maximum 69 Number | Solution | | Easy | Math |
1317 | Convert Integer to the Sum of Two No-Zero Integers | Solution | | Easy | |
1315 | Sum of Nodes with Even-Valued Grandparent | Solution | | Medium | Tree, DFS |
1314 | Matrix Block Sum | Solution | | Medium | Dynamic Programming |
1313 | Decompress Run-Length Encoded List | Solution | | Easy | Array |
1305 | All Elements in Two Binary Search Trees | Solution | | Medium | |
1304 | Find N Unique Integers Sum up to Zero | Solution | | Easy | |
1302 | Deepest Leaves Sum | Solution | | Medium | |
1300 | Sum of Mutated Array Closest to Target | Solution | | Medium | |
1299 | Replace Elements with Greatest Element on Right Side | Solution | | Easy | |
1297 | Maximum Number of Occurrences of a Substring | Solution | | Medium | |
1296 | Divide Array in Sets of K Consecutive Numbers | Solution | | Medium | |
1295 | Find Numbers with Even Number of Digits | JavaJavascript | 📺 | Easy | |
1291 | Sequential Digits | Solution | | Medium | |
1290 | Convert Binary Number in a Linked List to Integer | Solution | | Easy | |
1289 | Minimum Falling Path Sum II | Solution | | Hard | Dynamic Programming |
1287 | Element Appearing More Than 25% In Sorted Array | Solution | 📺 | Easy | |
1286 | Iterator for Combination | Solution | | Medium | Backtracking, Design |
1283 | Find the Smallest Divisor Given a Threshold | Solution | Medium | | |
1282 | Group the People Given the Group Size They Belong To | Solution | 📺 | Medium | |
1281 | Subtract the Product and Sum of Digits of an Integer | Solution | | Easy | |
1277 | Count Square Submatrices with All Ones | Solution | | Medium | |
1275 | Find Winner on a Tic Tac Toe Game | Solution | | Easy | Array |
1273 | Delete Tree Nodes | Solution | | Medium | Dynamic Programming, DFS |
1271 | Hexspeak | Solution | | Easy | |
1268 | Search Suggestions System | Solution | | Medium | String |
1267 | Count Servers that Communicate | Solution | | Medium | |
1266 | Minimum Time Visiting All Points | Solution | | Easy | |
1265 | Print Immutable Linked List in Reverse | Solution | | Medium | |
1261 | Find Elements in a Contaminated Binary Tree | Solution | | Medium | Tree, HashTable |
1260 | Shift 2D Grid | Solution | 📺 | Easy | |
1258 | Synonymous Sentences | Solution | | Medium | Backtracking |
1252 | Cells with Odd Values in a Matrix | Solution | | Easy | |
1237 | Find Positive Integer Solution for a Given Equation | Solution | | Easy | |
1243 | Array Transformation | Solution | 📺 | Easy | |
1232 | Check If It Is a Straight Line | Solution | 📺 | Easy | |
1228 | Missing Number In Arithmetic Progression | Solution | | Easy | |
1221 | Split a String in Balanced Strings | Solution | | Easy | Greedy |
1219 | Path with Maximum Gold | Solution | | Medium | Backtracking |
1217 | Play with Chips | Solution | | Easy | Array, Math, Greedy |
1214 | Two Sum BSTs | Solution | | Medium | Binary Search Tree |
1213 | Intersection of Three Sorted Arrays | Solution | 📺 | Easy | |
1209 | Remove All Adjacent Duplicates in String II | Solution | | Medium | Stack |
1207 | Unique Number of Occurrences | Solution | 📺 | Easy | |
1200 | Minimum Absolute Difference | Solution | 📺 | Easy | |
1198 | Find Smallest Common Element in All Rows | Solution | 📺 | Easy | |
1196 | How Many Apples Can You Put into the Basket | Solution | 📺 | Easy | |
1190 | Reverse Substrings Between Each Pair of Parentheses | Solution | | Medium | Stack |
1189 | Maximum Number of Balloons | Solution | 📺 | Easy | |
1185 | Day of the Week | Solution | | Easy | |
1184 | Distance Between Bus Stops | Solution | 📺 | Easy | |
1182 | Shortest Distance to Target Color | Solution | | Medium | Binary Search |
1180 | Count Substrings with Only One Distinct Letter | Solution | | Easy | Math, String |
1176 | Diet Plan Performance | Solution | | Easy | Array, Sliding Window |
1175 | Prime Arrangements | Solution | | Easy | |
1165 | Single-Row Keyboard | Solution | | Easy | |
1161 | Maximum Level Sum of a Binary Tree | Solution | | Medium | Graph |
1160 | Find Words That Can Be Formed by Characters | Solution | | Easy | |
1154 | Day of the Year | Solution | | Easy | |
1150 | Check If a Number Is Majority Element in a Sorted Array | Solution | 📺 | Easy | |
1146 | Snapshot Array | Javascript | | Easy | |
1138 | Alphabet Board Path | Solution | | Medium | HashTable, String |
1137 | N-th Tribonacci Number | Solution | | Easy | |
1134 | Armstrong Number | Solution | 📺 | Easy | |
1133 | Largest Unique Number | Solution | 📺 | Easy | |
1128 | Number of Equivalent Domino Pairs | Solution | 📺 | Easy | |
1122 | Relative Sort Array | Solution | | Easy | |
1170 | Compare Strings by Frequency of the Smallest Character | Solution | | Easy | |
1119 | Remove Vowels from a String | Solution | 📺 | Easy | |
1118 | Number of Days in a Month | Solution | | Easy | |
1114 | Print in Order | Solution | | Easy | |
1108 | Defanging an IP Address | Solution | 📺 | Easy | |
1104 | Path In Zigzag Labelled Binary Tree | Solution | | Medium | Math, Tree |
1103 | Distribute Candies to People | Solution | | Easy | Math |
1100 | Find K-Length Substrings With No Repeated Characters | Solution | | Medium | String, Sliding Window |
1099 | Two Sum Less Than K | Solution | 📺 | Easy | |
1090 | Largest Values From Labels | Solution | | Medium | HashTable, Greedy |
1089 | Duplicate Zeros | Solution | | Easy | |
1087 | Brace Expansion | Solution | | Medium | Backtracking |
1086 | High Five | Solution | 📺 | Easy | |
1085 | Sum of Digits in the Minimum Number | Solution | 📺 | Easy | |
1079 | Letter Tile Possibilities | Solution | | Medium | |
1078 | Occurrences After Bigram | Solution | | Easy | |
1071 | Greatest Common Divisor of Strings | Solution | | Easy | |
1066 | Campus Bikes II | Solution | | Medium | Backtracking, DP |
1065 | Index Pairs of a String | Solution | | Medium | |
1062 | Longest Repeating Substring | Solution | | Medium | |
1057 | Campus Bikes | Solution | | Medium | |
1056 | Confusing Number | Solution | | Easy | |
1055 | Fixed Point | Solution | | Easy | |
1051 | Height Checker | Solution | | Easy | |
1047 | Remove All Adjacent Duplicates In String | Solution | | Easy | |
1046 | Last Stone Weight | Solution | 📺 | Easy | |
1043 | Partition Array for Maximum Sum | Solution | | Medium | DP |
1038 | Binary Search Tree to Greater Sum Tree | Solution | | Medium | DFS, tree |
1037 | Valid Boomerang | Solution | | Easy | Math |
1033 | Moving Stones Until Consecutive | Solution | | Easy | Math |
1030 | Matrix Cells in Distance Order | Solution | | Easy | |
1029 | Two City Scheduling | Solution | | Easy | |
1025 | Divisor Game | Solution | | Easy | |
1022 | Sum of Root To Leaf Binary Numbers | Solution | | Easy | |
1021 | Remove Outermost Parentheses | Solution | | Easy | |
1020 | Number of Enclaves | Solution | | Medium | Graph, DFS, BFS, recursion |
1019 | Next Greater Node In Linked List | Solution | | Medium | Linked List, Stack |
1018 | Binary Prefix Divisible By 5 | Solution | | Easy | |
1014 | Best Sightseeing Pair | Solution | | Medium | |
1013 | Partition Array Into Three Parts With Equal Sum | Solution | | Easy | |
1011 | Capacity To Ship Packages Within D Days | Solution | | Medium | Binary Search |
1010 | Pairs of Songs With Total Durations Divisible by 60 | Solution | | Easy | |
1009 | Complement of Base 10 Integer | Solution | | Easy | |
1008 | Construct Binary Search Tree from Preorder Traversal | Solution | | Medium | Recursion |
1005 | Maximize Sum Of Array After K Negations | Solution | 📺 | Easy | |
1004 | Max Consecutive Ones III | Solution | 📺 | Medium | Two Pointers, Sliding Window |
1003 | Check If Word Is Valid After Substitutions | Solution | | Medium | |
1002 | Find Common Characters | Solution | | Easy | |
999 | Available Captures for Rook | Solution | | Easy | |
981 | Time Based Key-Value Store | Solution | | Medium | |
997 | Find the Town Judge | Solution | | Easy | |
994 | Rotting Oranges | Solution | | Easy | BFS |
993 | Cousins in Binary Tree | Solution | | Easy | Tree, BFS |
989 | Add to Array-Form of Integer | Solution | | Easy | Array |
988 | Smallest String Starting From Leaf | Solution | | Medium | Tree, DFS |
987 | Vertical Order Traversal of a Binary Tree | Solution | | Medium | Recursion |
986 | Interval List Intersections | Solution | | Medium | Two Pointers |
985 | Sum of Even Numbers After Queries | Solution | | Easy | Array |
980 | Unique Paths III | Solution | | Hard | Backtracking, DFS |
979 | Distribute Coins in Binary Tree | Solution | | Medium | Recursion |
977 | Squares of a Sorted Array | Solution | | Easy | Array |
976 | Largest Perimeter Triangle | Solution | | Easy | Math Array |
974 | Subarray Sums Divisible by K | Solution | | Medium | Array |
973 | K Closest Points to Origin | Solution | | Easy | Math Sort |
970 | Powerful Integers | Solution | | Easy | Math |
966 | Vowel Spellchecker | Solution | | Medium | Hash Table, String |
965 | Univalued Binary Tree | Solution | | Easy | DFS, recursion |
961 | N-Repeated Element in Size 2N Array | Solution | | Easy | |
958 | Check Completeness of a Binary Tree | Solution | | Medium | Tree |
957 | Prison Cells After N Days | Solution | 📺 | Medium | |
954 | Array of Doubled Pairs | Solution | 📺 | Medium | |
953 | Verifying an Alien Dictionary | Solution | | Easy | |
951 | Flip Equivalent Binary Trees | Solution | | Medium | Tree, DFS, recursion |
950 | Reveal Cards In Increasing Order | Solution | | Medium | |
946 | Validate Stack Sequences | Solution | | Medium | Stack |
944 | Delete Columns to Make Sorted | Solution | | Easy | |
942 | DI String Match | Solution | | Easy | |
941 | Valid Mountain Array | Solution | | Easy | |
938 | Range Sum of BST | Solution | | Medium | BST, recursion, DFS |
937 | Reorder Log Files | Solution | | Easy | |
935 | Knight Dialer | Solution | | Medium | |
933 | Number of Recent Calls | Solution | | Easy | |
931 | Minimum Falling Path Sum | Solution | | Medium | Dynamic Programming |
929 | Unique Email Addresses | Solution | | Easy | |
925 | Long Pressed Name | Solution | | Easy | |
922 | Sort Array By Parity II | Solution | | Easy | |
921 | Minimum Add to Make Parentheses Valid | Solution | | Medium | Stack, Greedy |
917 | Reverse Only Letters | Solution | | Easy | |
914 | X of a Kind in a Deck of Cards | Solution | | Easy | |
912 | Sort an Array | Solution | | Easy | |
908 | Smallest Range I | Solution | | Easy | |
901 | Online Stock Span | Solution | | Medium | Stack |
904 | Fruit Into Baskets | Solution | | Medium | Two Pointers |
900 | RLE Iterator | Solution | | Medium | |
897 | Increasing Order Search Tree | Solution | | Easy | DFS, recursion |
896 | Monotonic Array | Solution | | Easy | |
890 | Find and Replace Pattern | Solution | | Medium | |
893 | Groups of Special-Equivalent Strings | Solution | 📺 | Easy | |
888 | Fair Candy Swap | Solution | | Easy | |
885 | Spiral Matrix III | Solution | 📺 | Medium | |
884 | Uncommon Words from Two Sentences | Solution | | Easy | |
883 | Projection Area of 3D Shapes | Solution | | Easy | Math |
880 | Decoded String at Index | Solution | | Medium | Stack |
876 | Middle of the Linked List | Solution | | Easy | |
872 | Leaf-Similar Trees | Solution | | Easy | DFS, recursion |
868 | Binary Gap | Solution | | Easy | |
867 | Transpose Matrix | Solution | | Easy | |
860 | Lemonade Change | Solution | | Easy | |
859 | Buddy Strings | Solution | | Easy | |
856 | Score of Parentheses | Solution | | Medium | Stack, String |
852 | Peak Index in a Mountain Array | Solution | | Easy | |
849 | Maximize Distance to Closest Person | Solution | | Easy | |
844 | Backspace String Compare | Solution | | Easy | |
841 | Keys and Rooms | Solution | | Easy | DFS, Graph |
840 | Magic Squares In Grid | Solution | | Easy | |
836 | Rectangle Overlap | Solution | 📺 | Easy | |
832 | Flipping an Image | Solution | | Easy | |
830 | Positions of Large Groups | Solution | | Easy | |
824 | Goat Latin | Solution | | Easy | |
821 | Shortest Distance to a Character | Solution | | Easy | |
819 | Most Common Word | Solution | | Easy | HashMap |
814 | Binary Tree Pruning | Solution | | Medium | recursion, DFS |
811 | Subdomain Visit Count | Solution | | Easy | HashMap |
807 | Max Increase to Keep City Skyline | Solution | | Medium | |
806 | Number of Lines To Write String | Solution | | Easy | |
804 | Unique Morse Code Words | Solution | | Easy | |
800 | Similar RGB Color | Solution | | Easy | |
799 | Champagne Tower | Solution | | Medium | |
796 | Rotate String | Solution | | Easy | |
791 | Custom Sort String | Solution | | Medium | |
789 | Escape The Ghosts | Solution | | Medium | Math |
788 | Rotated Digits | Solution | | Easy | |
784 | Letter Case Permutation | Solution | | Easy | |
783 | Minimum Distance Between BST Nodes | Solution | | Easy | |
781 | Rabbits in Forest | Solution | | Medium | HashTable, Math |
779 | K-th Symbol in Grammar | Solution | | Medium | |
776 | Split BST | Solution | | Medium | Recursion |
771 | Jewels and Stones | Solution | | Easy | |
769 | Max Chunks To Make Sorted | Solution | | Medium | Array |
767 | Reorganize String | Solution | | Medium | |
766 | Toeplitz Matrix | Solution | | Easy | |
765 | Couples Holding Hands | Solution | | Hard | |
764 | Largest Plus Sign | Solution | | Medium | DP |
763 | Partition Labels | Solution | | Medium | |
762 | Prime Number of Set Bits in Binary Representation | Solution | | Easy | |
760 | Find Anagram Mappings | Solution | | Easy | |
758 | Bold Words in String | Solution | | Easy | |
757 | Set Intersection Size At Least Two | Solution | | Hard | |
756 | Pyramid Transition Matrix | Solution | | Medium | Backtracking |
755 | Pour Water | Solution | | Medium | Array |
754 | Reach a Number | Solution | | Medium | Math |
750 | Number Of Corner Rectangles | Solution | | Medium | |
748 | Shortest Completing Word | Solution | | Easy | |
747 | Largest Number Greater Than Twice of Others | Solution | | Easy | |
746 | Min Cost Climbing Stairs | Solution | | Easy | |
744 | Find Smallest Letter Greater Than Target | Solution | | Easy | |
743 | Network Delay Time | Solution | | Medium | Graph, Djikstra |
742 | Closest Leaf in a Binary Tree | Solution | | Medium | Tree |
740 | Delete and Earn | Solution | | Medium | |
739 | Daily Temperatures | Solution | | Medium | |
738 | Monotone Increasing Digits | Solution | | Medium | |
737 | Sentence Similarity II | Solution | | Medium | Union Find |
735 | Asteroid Collision | Solution | | Medium | Stack |
734 | Sentence Similarity | Solution | | Easy | HashTable |
733 | Flood Fill | Solution | | Easy | BFS, DFS |
729 | My Calendar I | Solution | | Medium | |
728 | Self Dividing Numbers | Solution | | Easy | |
727 | Minimum Window Subsequence | Solution | | Hard | DP |
725 | Split Linked List in Parts | Solution | | Medium | LinkedList |
724 | Find Pivot Index | Solution | | Easy | Array |
723 | Candy Crush | Solution | | Medium | Array, Two Pointers |
721 | Accounts Merge | Solution | | Medium | DFS, Union Find |
720 | Longest Word in Dictionary | Solution | | Easy | Trie |
719 | Find K-th Smallest Pair Distance | Solution | | Hard | Binary Search |
718 | Maximum Length of Repeated Subarray | Solution | | Medium | DP |
717 | 1-bit and 2-bit Characters | Solution | | Easy | |
716 | Max Stack | Solution | | Hard | Design |
714 | Best Time to Buy and Sell Stock with Transaction Fee | Solution | | Medium | DP |
713 | Subarray Product Less Than K | Solution | | Medium | |
712 | Minimum ASCII Delete Sum for Two Strings | Solution | | Medium | DP |
709 | To Lower Case | Solution | | Easy | String |
706 | Design HashMap | Solution | | Easy | Design |
705 | Design HashSet | Solution | | Easy | Design |
704 | Binary Search | Solution | | Easy | Binary Search |
703 | Kth Largest Element in a Stream | Solution | | Easy | |
701 | Insert into a Binary Search Tree | Solution | | Medium | DFS, recursion |
700 | Search in a Binary Search Tree | Solution | | Easy | recusion, dfs |
699 | Falling Squares | Solution | | Hard | Segment Tree |
698 | Partition to K Equal Sum Subsets | Solution,C++ | | Medium | Backtracking + DP |
697 | Degree of an Array | Solution | | Easy | |
696 | Count Binary Substrings | Solution | | Easy | |
695 | Max Area of Island | Solution | | Easy | DFS |
694 | Number of Distinct Islands | Solution | | Medium | DFS |
693 | Binary Number with Alternating Bits | Solution | | Easy | |
692 | Top K Frequent Words | Solution | | Medium | |
691 | Stickers to Spell Word | Solution | | Hard | DP |
690 | Employee Importance | Solution | | Easy | DFS |
689 | Maximum Sum of 3 Non-Overlapping Subarrays | Solution | | Hard | DP |
688 | Knight Probability in Chessboard | Solution | | Medium | DP |
687 | Longest Univalue Path | Solution | | Easy | DFS |
686 | Repeated String Match | Solution | | Easy | |
685 | Redundant Connection II | Solution | | Hard | Union Find |
684 | Redundant Connection | Solution | | Medium | Union Find |
683 | K Empty Slots | Solution | | Hard | |
682 | Baseball Game | Solution | | Easy | |
681 | Next Closest Time | Solution | | Medium | |
680 | Valid Palindrome II | Solution | | Easy | String |
679 | 24 Game | Solution | | Hard | Recursion |
678 | Valid Parenthesis String | Solution | | Medium | Recursion, Greedy |
677 | Map Sum Pairs | Solution | | Medium | HashMap, Trie |
676 | Implement Magic Dictionary | Solution | | Medium | |
675 | Cut Off Trees for Golf Event | Solution | | Hard | BFS |
674 | Longest Continuous Increasing Subsequence | Solution | | Easy | |
673 | Number of Longest Increasing Subsequence | Solution | | Medium | DP |
672 | Bulb Switcher II | Solution | | Medium | Math |
671 | Second Minimum Node In a Binary Tree | Solution | | Easy | Tree, DFS |
670 | Maximum Swap | Solution | | Medium | String |
669 | Trim a Binary Search Tree | Solution | | Easy | Tree, DFS |
668 | Kth Smallest Number in Multiplication Table | Solution | | Hard | Binary Search |
667 | Beautiful Arrangement II | Solution | | Medium | Array |
666 | Path Sum IV | Solution | | Medium | Tree, DFS |
665 | Non-decreasing Array | Solution | | Easy | |
664 | Strange Printer | Solution | | Hard | DP |
663 | Equal Tree Partition | Solution | | Medium | Tree |
662 | Maximum Width of Binary Tree | Solution | | Medium | BFS, DFS |
661 | Image Smoother | Solution | | Easy | Array |
660 | Remove 9 | Solution | | Hard | Math |
659 | Split Array into Consecutive Subsequences | Solution | | Medium | HashMap |
658 | Find K Closest Elements | Solution | | Medium | |
657 | Judge Route Circle | Solution | | Easy | |
656 | Coin Path | Solution | | Hard | DP |
655 | Print Binary Tree | Solution | | Medium | Recursion |
654 | Maximum Binary Tree | Solution | | Medium | Tree |
653 | Two Sum IV - Input is a BST | Solution | | Easy | Tree |
652 | Find Duplicate Subtrees | Solution | | Medium | Tree |
651 | 4 Keys Keyboard | Solution | | Medium | DP |
650 | 2 Keys Keyboard | Solution | | Medium | DP |
649 | Dota2 Senate | Solution | | Medium | Greedy |
648 | Replace Words | Solution | | Medium | Trie |
647 | Palindromic Substrings | Solution | | Medium | DP |
646 | Maximum Length of Pair Chain | Solution | | Medium | DP, Greedy |
645 | Set Mismatch | Solution | | Easy | |
644 | Maximum Average Subarray II | Solution | | Hard | Binary Search |
643 | Maximum Average Subarray I | Solution | | Easy | |
642 | Design Search Autocomplete System | Solution | | Hard | Design |
640 | Solve the Equation | Solution | | Medium | |
639 | Decode Ways II | Solution | | Hard | DP |
638 | Shopping Offers | Solution | | Medium | DP, DFS |
637 | Average of Levels in Binary Tree | Solution | | Easy | |
636 | Exclusive Time of Functions | Solution | | Medium | Stack |
635 | Design Log Storage System | Solution | | Medium | Design |
634 | Find the Derangement of An Array | Solution | | Medium | Math |
633 | Sum of Square Numbers | Solution | | Easy | Binary Search |
632 | Smallest Range | Solution | | Hard | Heap |
631 | Design Excel Sum Formula | Solution | | Hard | Design, Topological Sort |
630 | Course Schedule III | Solution | | Hard | Heap, Greedy |
629 | K Inverse Pairs Array | Solution | | Hard | DP |
628 | Maximum Product of Three Numbers | Solution | | Easy | |
625 | Minimum Factorization | Solution | | Medium | |
624 | Maximum Distance in Arrays | Solution | | Easy | Sort, Array |
623 | Add One Row to Tree | Solution | | Medium | Tree |
621 | Task Scheduler | Solution | | Medium | Greedy, Queue |
617 | Merge Two Binary Trees | Solution | | Easy | Tree, Recursion |
616 | Add Bold Tag in String | Solution | | Medium | String |
611 | Valid Triangle Number | Solution | | Medium | Binary Search |
609 | Find Duplicate File in System | Solution | | Medium | HashMap |
606 | Construct String from Binary Tree | Solution | | Easy | Tree, Recursion |
605 | Can Place Flowers | Solution | | Easy | Array |
604 | Design Compressed String Iterator | Solution | | Easy | Design, String |
600 | Non-negative Integers without Consecutive Ones | Solution | | Hard | Bit Manipulation, DP |
599 | Minimum Index Sum of Two Lists | Solution | | Easy | HashMap |
598 | Range Addition II | Solution | | Easy | |
594 | Longest Harmonious Subsequence | Solution | | Easy | Array, HashMap |
593 | Valid Square | Solution,Javascript | | Medium | Math |
592 | Fraction Addition and Subtraction | Solution | | Medium | Math |
591 | Tag Validator | Solution | | Hard | Stack, String |
590 | N-ary Tree Postorder Traversal | Solution | | Easy | DFS, recursion |
589 | N-ary Tree Preorder Traversal | Solution | | Easy | DFS, recursion |
588 | Design In-Memory File System | Solution | | Hard | Trie, Design |
587 | Erect the Fence | Solution | | Hard | Geometry |
583 | Delete Operation for Two Strings | Solution | | Medium | DP |
582 | Kill Process | Solution | | Medium | Stack |
581 | Shortest Unsorted Continuous Subarray | Solution | | Easy | Array, Sort |
576 | Out of Boundary Paths | Solution | | Hard | DP, DFS |
575 | Distribute Candies | Solution | | Easy | Array |
573 | Squirrel Simulation | Solution | | Medium | Math |
572 | Subtree of Another Tree | Solution | | Easy | Tree |
568 | Maximum Vacation Days | Solution | | Hard | DP |
567 | Permutation in String | Solution | | Medium | Sliding Windows, Two Pointers |
566 | Reshape the Matrix | Solution | | Easy | |
565 | Array Nesting | Solution | | Medium | |
563 | Binary Tree Tilt | Solution | | Easy | Tree Recursion |
562 | Longest Line of Consecutive One in Matrix | Solution | | Medium | Matrix DP |
561 | Array Partition I | Solution | | Easy | Array |
560 | Subarray Sum Equals K | Solution | | Medium | Array, HashMap |
559 | Maximum Depth of N-ary Tree | Solution | | Easy | DFS, recursion |
557 | Reverse Words in a String III | Solution | | Easy | String |
556 | Next Greater Element III | Solution | | Medium | String |
555 | Split Concatenated Strings | Solution | | Medium | String |
554 | Brick Wall | Solution | | Medium | HashMap |
553 | Optimal Division | Solution | | Medium | String, Math |
552 | Student Attendance Record II | Solution | | Hard | DP |
551 | Student Attendance Record I | Solution | | Easy | String |
549 | Binary Tree Longest Consecutive Sequence II | Solution | | Medium | Tree |
548 | Split Array with Equal Sum | Solution | | Medium | Array |
547 | Friend Circles | Solution | | Medium | Union Find |
546 | Remove Boxes | Solution | | Hard | DFS, DP |
545 | Boundary of Binary Tree | Solution | | Medium | Recursion |
544 | Output Contest Matches | Solution | | Medium | Recursion |
543 | Diameter of Binary Tree | Solution | | Easy | Tree/DFS/Recursion |
542 | 01 Matrix | Solution | | Medium | BFS |
541 | Reverse String II | Solution | | Easy | String |
540 | Single Element in a Sorted Array | Solution | | Medium | |
539 | Minimum Time Difference | Solution | | Medium | String |
538 | Convert BST to Greater Tree | Solution | | Easy | Tree |
537 | Complex Number Multiplication | Solution | | Medium | Math, String |
536 | Construct Binary Tree from String | Solution | | Medium | Recursion, Stack |
535 | Encode and Decode TinyURL | Solution | | Medium | Design |
533 | Lonely Pixel II | Solution | | Medium | HashMap |
532 | K-diff Pairs in an Array | Solution | | Easy | HashMap |
531 | Lonely Pixel I | Solution | | Medium | |
530 | Minimum Absolute Difference in BST | Solution | | Easy | DFS |
529 | Minesweeper | Solution | | Medium | BFS |
527 | Word Abbreviation | Solution | | Hard | |
526 | Beautiful Arrangement | Solution | | Medium | Backtracking |
525 | Contiguous Array | Solution | | Medium | HashMap |
524 | Longest Word in Dictionary through Deleting | Solution | | Medium | Sort |
523 | Continuous Subarray Sum | Solution | | Medium | DP |
522 | Longest Uncommon Subsequence II | Solution | | Medium | |
521 | Longest Uncommon Subsequence I | Solution | | Easy | |
520 | Detect Capital | Solution | | Easy | |
517 | Super Washing Machines | Solution | | Hard | DP |
516 | Longest Palindromic Subsequence | Solution | | Medium | DP |
515 | Find Largest Value in Each Tree Row | Solution | | Medium | BFS |
514 | Freedom Trail | Solution | | Hard | DP |
513 | Find Bottom Left Tree Value | Solution | | Medium | BFS |
509 | Fibonacci Number | Solution | 📺 | Easy | Array |
508 | Most Frequent Subtree Sum | Solution | | Medium | DFS, Tree |
507 | Perfect Number | Solution | | Easy | Math |
506 | Relative Ranks | Solution | | Easy | |
505 | The Maze II | Solution | | Medium | BFS |
504 | Base 7 | Solution | | Easy | |
503 | Next Greater Element II | Solution | | Medium | Stack |
502 | IPO | Solution | | Hard | Heap, Greedy |
501 | Find Mode in Binary Tree | Solution | | Easy | Binary Tree |
500 | Keyboard Row | Solution | | Easy | |
499 | The Maze III | Solution | | Hard | BFS |
496 | Next Greater Element I | Solution | | Easy | |
498 | Diagonal Traverse | Solution | | Medium | |
495 | Teemo Attacking | Solution | | Medium | Array |
494 | Target Sum | Solution | | Medium | |
493 | Reverse Pairs | Solution | | Hard | Recursion |
492 | Construct the Rectangle | Solution | | Easy | Array |
491 | Increasing Subsequences | Solution | | Medium | Backtracking, DFS |
490 | The Maze | Solution | | Medium | BFS |
488 | Zuma Game | Solution | | Hard | DFS, Backtracking |
487 | Max Consecutive Ones II | Solution | 📺 | Medium | Array |
486 | Predict the Winner | Solution | | Medium | DP |
485 | Max Consecutive Ones | JavaJavascript | 📺 | Easy | Array |
484 | Find Permutation | Solution | | Medium | Array, String, Greedy |
483 | Smallest Good Base | Solution | | Hard | Binary Search, Math |
482 | License Key Formatting | Solution | | Medium | |
481 | Magical String | Solution | | Medium | |
480 | Sliding Window Median | Solution | | Hard | Heap |
479 | Largest Palindrome Product | Solution | | Easy | |
477 | Total Hamming Distance | Solution | | Medium | Bit Manipulation |
476 | Number Complement | Solution | | Easy | Bit Manipulation |
475 | Heaters | Solution | | Easy | Array Binary Search |
474 | Ones and Zeroes | Solution | | Medium | DP |
473 | Matchsticks to Square | Solution | | Medium | Backtracking, DFS |
472 | Concatenated Words | Solution | | Hard | Trie, DP, DFS |
471 | Encode String with Shortest Length | Solution | | Hard | DP |
469 | Convex Polygon | Solution | | Medium | Math |
468 | Validate IP Address | Solution | | Medium | String |
467 | Unique Substrings in Wraparound String | Solution | | Medium | DP |
466 | Count The Repetitions | Solution | | Hard | DP |
465 | Optimal Account Balancing | Solution | | Hard | DP |
464 | Can I Win | Solution | | Medium | DP |
463 | Island Perimeter | Solution | | Easy | |
462 | Minimum Moves to Equal Array Elements II | Solution | | Medium | |
461 | Hamming Distance | Solution,C++ | | Easy | |
460 | LFU Cache | Solution | | Hard | Design, LinkedHashMap, HashMap |
459 | Repeated Substring Pattern | Solution | | Easy | String, KMP |
458 | Poor Pigs | Solution | | Easy | Math |
457 | Circular Array Loop | Solution | | Medium | |
456 | 132 Pattern | Solution | | Medium | Stack |
455 | Assign Cookies | Solution | | Easy | |
454 | 4Sum II | Solution | | Medium | HashMap |
453 | Minimum Moves to Equal Array Elements | Solution | | Easy | |
452 | Minimum Number of Arrows to Burst Balloons | Solution | | Medium | Array, Greedy |
451 | Sort Characters By Frequency | Solution | | Medium | HashMap |
450 | Delete Node in a BST | Solution | | Medium | Tree, Recursion |
449 | Serialize and Deserialize BST | Solution | | Medium | BFS |
448 | Find All Numbers Disappeared in an Array | Solution | | Easy | Array, HashMap |
447 | Number of Boomerangs | Solution | | Easy | HashMap |
446 | Arithmetic Slices II - Subsequence | Solution | | Hard | DP |
445 | Add Two Numbers II | Solution | | Medium | Stack, LinkedList |
444 | Sequence Reconstruction | Solution | | Medium | Topological Sort, Graph |
443 | String Compression | Solution | | Easy | |
442 | Find All Duplicates in an Array | Solution | | Medium | Array |
441 | Arranging Coins | Solution | | Easy | |
440 | K-th Smallest in Lexicographical Order | Solution | | Hard | |
439 | Ternary Expression Parser | Solution | | Medium | Stack |
438 | Find All Anagrams in a String | Solution | | Easy | Sliding Window |
437 | Path Sum III | Solution | | Easy | DFS, recursion |
436 | Find Right Interval | Solution | | Medium | Binary Search |
435 | Non-overlapping Intervals | Solution | | Medium | Greedy |
434 | Number of Segments in a String | Solution | | Easy | |
432 | All O`one Data Structure | Solution | | Hard | Design |
429 | N-ary Tree Level Order Traversal | Solution | | Easy | BFS, Tree |
425 | Word Squares | Solution | | Hard | Trie, Backtracking, Recursion |
424 | Longest Repeating Character Replacement | Solution | | Medium | Sliding Window |
423 | Reconstruct Original Digits from English | Solution | | Medium | Math |
422 | Valid Word Square | Solution | | Easy | |
421 | Maximum XOR of Two Numbers in an Array | Solution | | Medium | Bit Manipulation, Trie |
420 | Strong Password Checker | Solution | | Hard | |
419 | Battleships in a Board | Solution | | Medium | DFS |
418 | Sentence Screen Fitting | Solution | | Medium | |
417 | Pacific Atlantic Water Flow | Solution | | Medium | DFS |
416 | Partition Equal Subset Sum | Java,C++ | | Medium | DP |
415 | Add Strings | Solution | | Easy | |
414 | Third Maximum Number | Solution | | Easy | |
413 | Arithmetic Slices | Solution | | Medium | DP |
412 | Fizz Buzz | Solution | | Easy | |
411 | Minimum Unique Word Abbreviation | Solution | | Hard | NP-Hard, Backtracking, Trie, Recursion |
410 | Split Array Largest Sum | Solution | | Hard | Binary Search, DP |
409 | Longest Palindrome | Solution | | Easy | |
408 | Valid Word Abbreviation | Solution | | Easy | |
407 | Trapping Rain Water II | Solution | | Hard | Heap |
406 | Queue Reconstruction by Height | Solution | | Medium | LinkedList, PriorityQueue |
405 | Convert a Number to Hexadecimal | Solution | | Easy | |
404 | Sum of Left Leaves | Solution | | Easy | |
403 | Frog Jump | Solution | | Hard | DP |
402 | Remove K Digits | Solution | | Medium | Greedy, Stack |
401 | Binary Watch | Solution | | Easy | |
400 | Nth Digit | Solution | | Easy | |
399 | Evaluate Division | Solution | | Medium | Graph, DFS, Backtracking |
398 | Random Pick Index | Solution | | Medium | Reservoir Sampling |
397 | Integer Replacement | Solution | | Easy | BFS |
396 | Rotate Function | Solution | | Easy | |
395 | Longest Substring with At Least K Repeating Characters | Solution | | Medium | Recursion |
394 | Decode String | Solution | | Medium | Stack Depth-first-search |
393 | UTF-8 Validation | Solution | | Medium | Bit Manipulation |
392 | Is Subsequence | Solution | | Medium | Array, String |
391 | Perfect Rectangle | Solution | | Hard | |
390 | Elimination Game | Solution | | Medium | |
389 | Find the Difference | Solution | | | Easy |
388 | Longest Absolute File Path | Solution | | Medium | Stack |
387 | First Unique Character in a String | Solution | | Easy | HashMap |
386 | Lexicographical Numbers | Solution | | Medium | |
385 | Mini Parser | Solution | | Medium | Stack |
384 | Shuffle an Array | Solution | | Medium | |
383 | Ransom Note | Solution | | Easy | String |
382 | Linked List Random Node | Solution | | Medium | Reservoir Sampling |
381 | Insert Delete GetRandom O(1) - Duplicates allowed | Solution | | Hard | |
380 | Insert Delete GetRandom O(1) | Solution | | Medium | Design, HashMap |
379 | Design Phone Directory | Solution | | Medium | |
378 | Kth Smallest Element in a Sorted Matrix | Solution | | Medium | Binary Search |
377 | Combination Sum IV | Solution | | Medium | DP |
376 | Wiggle Subsequence | Solution | | Medium | DP, Greedy |
375 | Guess Number Higher or Lower II | Solution | | Medium | DP |
374 | Guess Number Higher or Lower | Solution | | Easy | Binary Search |
373 | Find K Pairs with Smallest Sums | Solution | | Medium | Heap |
372 | Super Pow | Solution | | Medium | Math |
371 | Sum of Two Integers | Solution | | Easy | |
370 | Range Addition | Solution | | Medium | Array |
369 | Plus One Linked List | Solution | | Medium | Linked List |
368 | Largest Divisible Subset | Solution | | Medium | DP |
367 | Valid Perfect Square | Solution | | Medium | |
366 | Find Leaves of Binary Tree | Solution | | Medium | DFS |
365 | Water and Jug Problem | Solution | | Medium | Math |
364 | Nested List Weight Sum II | Solution | | Medium | DFS |
363 | Max Sum of Rectangle No Larger Than K | Solution | | Hard | DP |
362 | Design Hit Counter | Solution | | Medium | Design |
361 | Bomb Enemy | Solution | | Medium | |
360 | Sort Transformed Array | Solution | | Medium | Two Pointers, Math |
359 | Logger Rate Limiter | Solution | | Easy | HashMap |
358 | Rearrange String k Distance Apart | Solution | | Hard | HashMap, Heap, Greedy |
357 | Count Numbers with Unique Digits | Solution | | Medium | DP, Math |
356 | Line Reflection | Solution | | Medium | HashSet |
355 | Design Twitter | Solution | | Medium | Design, HashMap, Heap |
354 | Russian Doll Envelopes | Solution | | Hard | DP, Binary Search |
353 | Design Snake Game | Solution | | Medium | |
352 | Data Stream as Disjoint Intervals | Solution | | Hard | TreeMap |
351 | Android Unlock Patterns | Solution | | Medium | |
350 | Intersection of Two Arrays II | Solution | 📺 | Easy | HashMap, Binary Search |
349 | Intersection of Two Arrays | Solution | 📺 | Easy | Two Pointers, Binary Search |
348 | Design Tic-Tac-Toe | Solution | | Medium | Design |
347 | Top K Frequent Elements | Solution | | Medium | HashTable, Heap, Bucket Sort |
346 | Moving Average from Data Stream | Solution | | Easy | Queue |
345 | Reverse Vowels of a String | Solution | | Easy | String |
344 | Reverse String | Solution | 📺 | Easy | String |
343 | Integer Break | Solution | | Medium | Math |
342 | Power of Four | Solution | | Easy | Math |
341 | Flatten Nested List Iterator | Solution | | Medium | Stack |
340 | Longest Substring with At Most K Distinct Characters | Solution | | Hard | Sliding Window |
339 | Nested List Weight Sum | Solution | | Easy | DFS |
338 | Counting Bits | Solution | | Medium | |
337 | House Robber III | Solution | | Medium | DP |
336 | Palindrome Pairs | Solution | | Hard | |
335 | Self Crossing | Solution | | Hard | Math |
334 | Increasing Triplet Subsequence | Solution | | Medium | |
333 | Largest BST Subtree | Solution | | Medium | Tree |
332 | Reconstruct Itinerary | Solution | | Medium | Graph, DFS |
331 | Verify Preorder Serialization of a Binary Tree | Solution | | Medium | Stack |
330 | Patching Array | Solution | | Hard | Greedy |
329 | Longest Increasing Path in a Matrix | Solution | | Hard | DFS, DP |
328 | Odd Even Linked List | Solution | | Medium | Linked List |
327 | Count of Range Sum | Solution | | Hard | BST, Divide and Conquer |
326 | Power of Three | Solution | | Easy | Math |
325 | Maximum Size Subarray Sum Equals k | Solution | | Medium | HashTable |
324 | Wiggle Sort II | Solution | | Medium | Sort |
323 | Number of Connected Components in an Undirected Graph | Solution | | Medium | |
322 | Coin Change | Solution | | Medium | DP |
321 | Create Maximum Number | Solution | | Hard | |
320 | Generalized Abbreviation | Solution | | Medium | Backtracking, Bit Manipulation |
319 | Bulb Switcher | Solution | | Medium | Brainteaser |
318 | Maximum Product of Word Lengths | Solution | | Medium | |
317 | Shortest Distance from All Buildings | Solution | | Hard | |
316 | Remove Duplicate Letters | Solution | | Hard | Stack, Recursion, Greedy |
315 | Count of Smaller Numbers After Self | Solution | | Hard | Tree |
314 | Binary Tree Vertical Order Traversal | Solution | | Medium | HashMap, BFS |
313 | Super Ugly Number | Solution | | Medium | |
312 | Burst Balloons | Solution | | Hard | DP |
311 | Sparse Matrix Multiplication | Solution | | Medium | |
310 | Minimum Height Trees | Solution | | Medium | |
309 | Best Time to Buy and Sell Stock with Cooldown | Solution | | Medium | DP |
308 | Range Sum Query 2D - Mutable | Solution | | Hard | Tree |
307 | Range Sum Query - Mutable | Solution | | Medium | Tree |
306 | Additive Number | Solution | | Medium | |
305 | Number of Islands II | Solution | | Hard | Union Find |
304 | Range Sum Query 2D - Immutable | Solution | | Medium | |
303 | Range Sum Query - Immutable | Solution | | Easy | |
302 | Smallest Rectangle Enclosing Black Pixels | Solution | | Hard | DFS, BFS |
301 | Remove Invalid Parentheses | Solution | | Hard | BFS |
300 | Longest Increasing Subsequence | Solution | | Medium | DP |
299 | Bulls and Cows | Solution | | Easy | |
298 | Binary Tree Longest Consecutive Sequence | Solution | | Medium | Tree |
297 | Serialize and Deserialize Binary Tree | Solution | | Hard | BFS |
296 | Best Meeting Point | Solution | | Hard | |
295 | Find Median from Data Stream | Solution | | Hard | Heap |
294 | Flip Game II | Solution | | Medium | Backtracking |
293 | Flip Game | Solution | | Easy | |
292 | Nim Game | Solution | | Easy | |
291 | Word Pattern II | Solution | | Hard | Recursion, Backtracking |
290 | Word Pattern | Solution | | Easy | HashMap |
289 | Game of Life | Solution | 📺 | Medium | |
288 | Unique Word Abbreviation | Solution | | Easy | |
287 | Find the Duplicate Number | Solution | | Medium | |
286 | Walls and Gates | Solution | | Medium | BFS |
285 | Inorder Successor In BST | Solution | | Medium | Tree |
284 | Peeking Iterator | Solution | | Medium | Design |
283 | Move Zeroes | Solution | 📺 | Easy | |
282 | Expression Add Operators | Solution | | Hard | |
281 | Zigzag Iterator | Solution | | Medium | |
280 | Wiggle Sort | Solution | | Medium | |
279 | Perfect Squares | Solution | | Medium | |
278 | First Bad Version | Solution | 📺 | Easy | Binary Search |
277 | Find the Celebrity | Solution | | Medium | |
276 | Paint Fence | Solution | | Easy | DP |
275 | H-Index II | Solution | | Medium | Binary Search |
274 | H-Index | Solution | | Medium | |
273 | Integer to English Words | Solution | | Hard | Math, String |
272 | Closest Binary Search Tree Value II | Solution | | Hard | Stack |
271 | Encode and Decode Strings | Solution | | | Medium |
270 | Closest Binary Search Tree Value | Solution | | | Easy |
269 | Alien Dictionary | Solution | | | Hard |
268 | Missing Number | Solution | | | Easy |
267 | Palindrome Permutation II | Solution | | Medium | |
266 | Palindrome Permutation | Solution | | Easy | |
265 | Paint House II | Solution | | Hard | DP |
264 | Ugly Number II | Solution | | Medium | DP |
263 | Ugly Number | Solution | | Easy | |
261 | Graph Valid Tree | Solution | | Medium | |
260 | Single Number III | Solution | | Medium | |
259 | 3Sum Smaller | Solution | | Medium | |
258 | Add Digits | Solution | | Easy | |
257 | Binary Tree Paths | Solution | | | DFS/Recursion |
256 | Paint House | Solution | | Medium | DP |
255 | Verify Preorder Sequence in Binary Search Tree | Solution | | Medium | Tree |
254 | Factor Combinations | Solution | | Medium | Backtracking |
253 | Meeting Rooms II | Solution | | Medium | Heap |
252 | Meeting Rooms | Solution | | Easy | |
251 | Flatten 2D Vector | Solution | | Medium | |
250 | Count Univalue Subtrees | Solution | | Medium | DFS |
249 | Group Shifted Strings | Solution | | | |
248 | Strobogrammatic Number III | Solution | | Hard | Recursion, DFS |
247 | Strobogrammatic Number II | Solution | | Medium | Recursion |
246 | Strobogrammatic Number | Solution | | Easy | |
245 | Shortest Word Distance III | Solution | | Medium | |
244 | Shortest Word Distance II | Solution | | Medium | HashMap |
243 | Shortest Word Distance | Solution | | Easy | |
242 | Valid Anagram | Solution | | Easy | |
241 | Different Ways to Add Parentheses | Solution | | Medium | Divide and Conquer |
240 | Search a 2D Matrix II | Solution | | Medium | Binary Search |
239 | Sliding Window Maximum | Solution | | Hard | Heap |
238 | Product of Array Except Self | Solution | | Medium | Array |
237 | Delete Node in a Linked List | Solution | 📺 | Easy | LinkedList |
236 | Lowest Common Ancestor of a Binary Tree | Solution | | Medium | DFS |
235 | Lowest Common Ancestor of a Binary Search Tree | Solution | | Easy | DFS |
234 | Palindrome Linked List | Solution | 📺 | Easy | Linked List |
233 | Number of Digit One | Solution | | Hard | Math |
232 | Implement Queue using Stacks | Solution | | Medium | Stack, Design |
231 | Power of Two | Solution | | Easy | |
230 | Kth Smallest Element in a BST | Solution | | Medium | Tree |
229 | Majority Element II | Solution | | Medium | |
228 | Summary Ranges | Solution | | Medium | Array |
227 | Basic Calculator II | Solution | | Medium | String |
226 | Invert Binary Tree | Solution | | Easy | DFS, recursion |
225 | Implement Stack using Queues | Solution | | Easy | Stack, Queue |
224 | Basic Calculator | Solution | | Hard | |
223 | Rectangle Area | Solution | | Easy | |
222 | Count Complete Tree Nodes | Solution | | Medium | Recursion |
221 | Maximal Square | Solution | | Medium | Recursion |
220 | Contains Duplicate III | Solution | 📺 | Medium | TreeSet |
219 | Contains Duplicate II | Solution | 📺 | Easy | HashMap |
218 | The Skyline Problem | Solution | | Hard | TreeMap, Design |
217 | Contains Duplicate | Solution | 📺 | Easy | HashSet |
216 | Combination Sum III | Solution | | Medium | Backtracking |
215 | Kth Largest Element in an Array | Solution | | Medium | Heap |
214 | Shortest Palindrome | Solution | | Hard | KMP |
213 | House Robber II | Solution | | Medium | DP |
212 | Word Search II | Solution | | Hard | Trie |
211 | Add and Search Word - Data structure design | Solution | | Medium | Trie |
210 | Course Schedule II | Solution | | Medium | |
209 | Minimum Size Subarray Sum | Solution | | Medium | |
208 | Implement Trie | Solution | 📺 | Medium | Trie |
207 | Course Schedule | Solution | | Medium | |
206 | Reverse Linked List | Solution | 📺 | Easy | Linked List |
205 | Isomorphic Strings | Solution | | Easy | |
204 | Count Primes | Solution | | Easy | The Sieve of Eratosthenes |
203 | Remove Linked List Elements | Solution | | Easy | |
202 | Happy Number | Solution | | Easy | |
201 | Bitwise AND of Numbers Range | Solution | | Medium | Bit Manipulation |
200 | Number of Islands | Solution | | Medium | Union Find, DFS |
199 | Binary Tree Right Side View | Solution | | Medium | BFS |
198 | House Robber | Solution | | Easy | DP |
191 | Number of 1 Bits | Solution | | Easy | Bit Manipulation |
190 | Reverse Bits | Solution | | Easy | Bit Manipulation |
189 | Rotate Array | Solution | 📺 | Easy | |
188 | Best Time to Buy and Sell Stock IV | Solution | | Hard | DP |
187 | Repeated DNA Sequences | Solution | | Medium | |
186 | Reverse Words in a String II | Solution | | Medium | |
179 | Largest Number | Solution | | Medium | |
174 | Dungeon Game | Solution | | Hard | DP |
173 | Binary Search Tree Iterator | Solution | | Medium | Stack, Design |
172 | Factorial Trailing Zeroes | Solution | | Easy | |
171 | Excel Sheet Column Number | Solution | | Easy | |
170 | Two Sum III - Data structure design | Solution | | Easy | |
169 | Majority Element | Solution | 📺 | Easy | |
168 | Excel Sheet Column Title | Solution | | Easy | |
167 | Two Sum II - Input array is sorted | Java,Javascript | | Easy | Binary Search |
166 | Fraction to Recurring Decimal | Solution | | Medium | HashMap |
165 | Compare Version Numbers | Solution | | Easy | |
164 | Maximum Gap | Solution | | Hard | |
163 | Missing Ranges | Solution | | | |
162 | Find Peak Element | Solution | | Binary Search | |
161 | One Edit Distance | Solution | | | |
160 | Intersection of Two Linked Lists | Solution | | Easy | Linked List |
159 | Longest Substring with At Most Two Distinct Characters | Solution | | Hard | String, Sliding Window |
158 | Read N Characters Given Read4 II - Call multiple times | Solution | | Hard | |
157 | Read N Characters Given Read4 | Solution | | Easy | |
156 | Binary Tree Upside Down | Solution | | Medium | Tree, Recursion |
155 | Min Stack | Solution | | Easy | Stack |
154 | Find Minimum in Rotated Sorted Array II | Solution | | Hard | Array, Binary Search |
153 | Find Minimum in Rotated Sorted Array | Solution | | Medium | Array, Binary Search |
152 | Maximum Product Subarray | Solution | | Medium | Array |
151 | Reverse Words in a String | Solution | | Medium | String |
150 | Evaluate Reverse Polish Notation | Solution | | Medium | |
149 | Max Points on a Line | Solution | | Hard | |
147 | Insertion Sort List | Solution | | Medium | Linked List |
146 | LRU Cache | Solution | | Hard | Doubly Linked List, LinkedHashMap |
145 | Binary Tree Postorder Traversal | Solution | 📺 | Hard | Binary Tree |
144 | Binary Tree Preorder Traversal | Solution | 📺 and📺 | Medium | Binary Tree |
143 | Reorder List | Solution | | Medium | |
142 | Linked List Cycle II | Solution | | Medium | Linked List |
141 | Linked List Cycle | Solution | 📺 | Easy | Linked List |
140 | Word Break II | Solution | | Hard | Backtracking/DFS |
139 | Word Break | Solution | 📺 | Medium | DP, Pruning |
138 | Copy List with Random Pointer | Solution | | Medium | LinkedList, HashMap |
137 | Single Number II | Solution | | Medium | Bit Manipulation |
136 | Single Number | Solution | 📺 | Easy | Bit Manipulation |
135 | Candy | Solution | | Hard | Greedy |
134 | Gas Station | Solution | | Medium | Greedy |
133 | Clone Graph | Solution | | Medium | HashMap, BFS, Graph |
132 | Palindrome Partitioning II | Solution | | Hard | |
131 | Palindrome Partitioning | Solution | | Medium | |
130 | Surrounded Regions | Solution | | Medium | |
129 | Sum Root to Leaf Numbers | Solution | | Medium | DFS |
128 | Longest Consecutive Sequence | Solution | | Hard | Union Find |
127 | Word Ladder | Solution | | Medium | BFS |
126 | Word Ladder II | Solution | | Hard | BFS |
125 | Valid Palindrome | Solution | | Easy | Two Pointers |
124 | Binary Tree Maximum Path Sum | Solution | | Hard | Tree, DFS |
123 | Best Time to Buy and Sell Stock III | Solution | | Hard | DP |
122 | Best Time to Buy and Sell Stock II | Solution | | Easy | Greedy |
121 | Best Time to Buy and Sell Stock | Solution | | Easy | |
120 | Triangle | Solution | | Medium | DP |
119 | Pascal's Triangle II | Solution | 📺 | Easy | |
118 | Pascal's Triangle | Solution | 📺 | Easy | |
117 | Populating Next Right Pointers in Each Node II | Solution | | Medium | BFS |
116 | Populating Next Right Pointers in Each Node | Solution | | Medium | BFS |
115 | Distinct Subsequences | Solution | | Hard | DP |
114 | Flatten Binary Tree to Linked List | Solution | | Medium | Tree |
113 | Path Sum II | Solution | | Medium | DFS, Backtracking |
112 | Path Sum | Solution | | Easy | DFS |
111 | Minimum Depth of Binary Tree | Solution | | Easy | BFS, DFS |
110 | Balanced Binary Tree | Solution | | Easy | DFS |
109 | Convert Sorted List to Binary Search Tree | Solution | | Medium | DFS, Recursion |
108 | Convert Sorted Array to Binary Search Tree | Solution | 📺 | Easy | Tree |
107 | Binary Tree Level Order Traversal II | Solution | | Easy | BFS |
106 | Construct Binary Tree from Inorder and Postorder Traversal | Solution | | Medium | Recursion, Tree |
105 | Construct Binary Tree from Preorder and Inorder Traversal | Solution | | Medium | Recursion, Tree |
104 | Maximum Depth of Binary Tree | Solution | 📺 | Easy | DFS |
103 | Binary Tree Zigzag Level Order Traversal | Solution | | Medium | BFS,DFS |
102 | Binary Tree Level Order Traversal | Solution | 📺 | Medium | BFS |
101 | Symmetric Tree | Solution | 📺 | Easy | DFS |
100 | Same Tree | Solution | 📺 | Easy | DFS |
99 | Recover Binary Search Tree | Solution | | Hard | |
98 | Validate Binary Search Tree | Solution | 📺 | Medium | DFS/Recursion |
97 | Interleaving String | Solution | | Hard | DP |
96 | Unique Binary Search Trees | Solution | | Medium | Recursion, DP |
95 | Unique Binary Search Trees II | Solution | | Medium | Recursion |
94 | Binary Tree Inorder Traversal | Solution | 📺📺 | Medium | Binary Tree |
93 | Restore IP Addresses | Solution | | Medium | Backtracking |
92 | Reverse Linked List II | Solution | | Medium | |
91 | Decode Ways | Solution | | Medium | DP |
90 | Subsets II | Solution | | Medium | Backtracking |
89 | Gray Code | Solution | | Medium | Bit Manipulation |
88 | Merge Sorted Array | Solution | | Easy | |
87 | Scramble String | Solution | | Hard | Recursion |
86 | Partition List | Solution | | Medium | Linked List |
85 | Maximal Rectangle | Solution | | Hard | DP |
84 | Largest Rectangle in Histogram | Solution | | Hard | Array, Stack |
83 | Remove Duplicates from Sorted List | Solution | | Easy | Linked List |
82 | Remove Duplicates from Sorted List II | Solution | | Medium | Linked List |
81 | Search in Rotated Sorted Array II | Solution | | Medium | Binary Search |
80 | Remove Duplicates from Sorted Array II | Solution | | Medium | |
79 | Word Search | Solution | | Medium | Backtracking, DFS |
78 | Subsets | Solution | | Medium | Backtracking |
77 | Combinations | Solution | | Medium | Backtracking |
76 | Minimum Window Substring | Solution | | Hard | Two Pointers |
75 | Sort Colors | Solution | | Medium | Two Pointers |
74 | Search a 2D Matrix | Solution | | Medium | Binary Search |
73 | Set Matrix Zeroes | Solution | | Medium | |
72 | Edit Distance | Solution | | Hard | |
71 | Simplify Path | Solution | | Medium | Stack |
70 | Climbing Stairs | Solution | 📺 | Easy | DP |
69 | Sqrt(x) | Solution | | Easy | |
68 | Text Justification | Solution | | Hard | |
67 | Add Binary | Solution | | Easy | |
66 | Plus One | Solution | 📺 | Easy | |
65 | Valid Number | Solution | | Hard | |
64 | Minimum Path Sum | Solution | | Medium | DP |
63 | Unique Paths II | Solution | | Medium | DP |
62 | Unique Paths | Solution | | Medium | DP |
61 | Rotate List | Solution | | Medium | Linked List |
60 | Permutation Sequence | Solution | | Medium | Math, Backtracking |
59 | Spiral Matrix II | Solution | 📺 | Medium | |
58 | Length of Last Word | Solution | | Easy | |
57 | Insert Intervals | Solution | | Hard | Array, Sort |
56 | Merge Intervals | Solution | | Medium | Array, Sort |
55 | Jump Game | Solution | | Medium | Greedy |
54 | Spiral Matrix | Solution | 📺 | Medium | Array |
53 | Maximum Subarray | Solution | | Easy | Array |
52 | N-Queens II | Solution | | Hard | Backtracking |
51 | N-Queens | Solution | | Hard | |
50 | Pow(x, n) | Solution | | Medium | |
49 | Group Anagrams | Solution | | Medium | HashMap |
48 | Rotate Image | Solution | 📺 | Medium | Array |
47 | Permutations II | Solution | | Medium | Backtracking |
46 | Permutations | Solution | | Medium | Backtracking |
45 | Jump Game II | Solution | | Hard | Array, Greedy |
44 | Wildcard Matching | Solution | | Hard | Backtracking, DP, Greedy, String |
43 | Multiply Strings | Solution | | Medium | Array, String |
42 | Trapping Rain Water | Solution | | Hard | |
41 | First Missing Positive | Solution | | Hard | Array |
40 | Combination Sum II | Solution | | Medium | Backtracking |
39 | Combination Sum | Solution | | Medium | Backtracking |
38 | Count and Say | Solution | | Easy | Recursion, LinkedList |
37 | Sudoku Solver | Solution | | Hard | |
36 | Valid Sudoku | Solution,Javascript | | Medium | |
35 | Search Insert Position | Solution | | Easy | Array |
34 | Search for a Range | Solution | | Medium | Array, Binary Search |
33 | Search in Rotated Sorted Array | Solution | | Medium | Binary Search |
32 | Longest Valid Parentheses | Solution | | Hard | Stack, DP |
31 | Next Permutation | Solution,C++ | | Medium | Array |
30 | Substring with Concatenation of All Words | Solution | | Hard | HashMap |
29 | Divide Two Integers | Solution | | Medium | |
28 | Implement strStr() | Solution | | Easy | String |
27 | Remove Element | Solution | | Easy | |
26 | Remove Duplicates from Sorted Array | Solution | 📺 | Easy | Array |
25 | Reverse Nodes in k-Group | Solution | | Hard | Recursion, LinkedList |
24 | Swap Nodes in Pairs | Solution | | Medium | Recursion, LinkedList |
23 | Merge k Sorted Lists | Solution | 📺 | Hard | Heap |
22 | Generate Parentheses | Solution | | Medium | Backtracking |
21 | Merge Two Sorted Lists | Solution | 📺 | Easy | Recursion |
20 | Valid Parentheses | Solution | 📺 | Easy | Stack |
19 | Remove Nth Node From End of List | Solution | 📺 | Medium | Linked List |
18 | 4 Sum | Solution | | Medium | Two Pointers |
17 | Letter Combinations of a Phone Number | Solution | | Medium | Backtracking |
16 | 3Sum Closest | Solution | | Medium | Two Pointers |
15 | 3Sum | Solution,C++ | 📺 | Medium | Two Pointers, Binary Search |
14 | Longest Common Prefix | Solution | 📺 | Easy | |
13 | Roman to Integer | Solution | | Easy | Math, String |
12 | Integer to Roman | Solution | | Medium | Math, String |
11 | Container With Most Water | Solution | | Medium | |
10 | Regular Expression Matching | Java,Javascript | | Hard | DP |
9 | Palindrome Number | Java,C++ | | Easy | |
8 | String to Integer (atoi) | Solution | | Medium | |
7 | Reverse Integer | Solution,C++ | 📺 | Easy | |
6 | ZigZag Conversion | Solution | | Easy | |
5 | Longest Palindromic Substring | Solution | | Medium | |
4 | Median of Two Sorted Arrays | Solution,C++ | | Hard | Divide and Conquer |
3 | Longest Substring Without Repeating Characters | Solution,C++ | | Medium | HashMap, Sliding Window |
2 | Add Two Numbers | Solution | | Medium | LinkedList |
1 | Two Sum | Java,C++,Javascript | 📺 | Easy | HashMap |