| 1 | Easy | Two Sum | 1-two-sum.cpp | O(n) | O(n) |
| 2 | Medium | Add Two Numbers | 2-add-two-numbers.cpp | O(n1+n2) | O(n1+n2) |
| 3 | Medium | Longest Substring Without Repeating Characters | 3-longest-substring-without-repeating-characters.cpp | O(n) | O(n) |
| 5 | Medium | Longest Palindromic Substring | 5-longest-palindromic-substring.cpp | O(n^2) | O(n) |
| 6 | Medium | Zigzag Conversion | 6-zigzag-conversion.cpp | O(n) | O(n) |
| 8 | Medium | String to Integer (atoi) | 8-string-to-integer-atoi.cpp | O(n) | O(1) |
| 9 | Easy | Palindrome Number | 9-palindrome-number.cpp | O(1) | O(1) |
| 19 | Medium | Remove Nth Node From End of List | 19-remove-nth-node-from-end-of-list.cpp | O(n) | O(1) |
| 20 | Easy | Valid Parentheses | 20-valid-parentheses.cpp | O(n) | O(n) |
| 21 | Easy | Merge Two Sorted Lists | 21-merge-two-sorted-lists.cpp | O(min(n1, n2)) | O(1) |
| 22 | Medium | Generate Parentheses | 22-generate-parentheses.cpp | O(C(n)), where C(n) = the n-th Catalan number | O(C(n)), where C(n) = the n-th Catalan number |
| 23 | Hard | Merge k Sorted Lists | 23-merge-k-sorted-lists.cpp | O(n*log(k)) | O(k) |
| 28 | Easy | Find the Index of the First Occurrence in a String | 28-find-the-index-of-the-first-occurrence-in-a-string.cpp | O(m+n) | O(m) |
| 31 | Medium | Next Permutation | 31-next-permutation.cpp | O(n) | O(1) |
| 33 | Medium | Search in Rotated Sorted Array | 33-search-in-rotated-sorted-array.cpp | O(log(n)) | O(log(n)) |
| 35 | Easy | Search Insert Position | 35-search-insert-position.cpp | O(log(n)) | O(1) |
| 39 | Medium | Combination Sum | 39-combination-sum.cpp | O(2^(n+t)*t) | O(2^(n+t)*t) |
| 46 | Medium | Permutations | 46-permutations.cpp | O(n*n!) | O(n*n!) |
| 48 | Medium | Rotate Image | 48-rotate-image.cpp | O(n^2) | O(1) |
| 49 | Medium | Group Anagrams | 49-group-anagrams.cpp | O(n*m*log(m)) | O(n*m) |
| 50 | Medium | Pow(x, n) | 50-powx-n.cpp | O(log(n)) | O(log(n)) |
| 53 | Medium | Maximum Subarray | 53-maximum-subarray.cpp | O(n) | O(1) |
| 55 | Medium | Jump Game | 55-jump-game.cpp | O(n) | O(1) |
| 62 | Medium | Unique Paths | 62-unique-paths.cpp | O(m*n) | O(m*n) |
| 63 | Medium | Unique Paths II | 63-unique-paths-ii.cpp | O(m*n) | O(m*n) |
| 64 | Medium | Minimum Path Sum | 64-minimum-path-sum.cpp | O(m*n) | O(m*n) |
| 70 | Easy | Climbing Stairs | 70-climbing-stairs.cpp | O(n) | O(n) |
| 75 | Medium | Sort Colors | 75-sort-colors.cpp | O(n) | O(1) |
| 76 | Hard | Minimum Window Substring | 76-minimum-window-substring.cpp | O(m+n) | O(m) |
| 77 | Medium | Combinations | 77-combinations.cpp | O(k*C(n,k)) | O(k*C(n,k)) |
| 78 | Medium | Subsets | 78-subsets.cpp | O(n*2^n) | O(n*2^n) |
| 82 | Medium | Remove Duplicates from Sorted List II | 82-remove-duplicates-from-sorted-list-ii.cpp | O(n) | O(1) |
| 83 | Easy | Remove Duplicates from Sorted List | 83-remove-duplicates-from-sorted-list.cpp | O(n) | O(1) |
| 88 | Easy | Merge Sorted Array | 88-merge-sorted-array.cpp | O(m+n) | O(1) |
| 91 | Medium | Decode Ways | 91-decode-ways.cpp | O(n) | O(n) |
| 94 | Easy | Binary Tree Inorder Traversal | 94-binary-tree-inorder-traversal.cpp | O(n) | O(n) |
| 95 | Medium | Unique Binary Search Trees II | 95-unique-binary-search-trees-ii.cpp | O(C(n)), where C(n) = the n-th Catalan number | O(C(n)) |
| 98 | Medium | Validate Binary Search Tree | 98-validate-binary-search-tree.cpp | O(n) | O(log(n)) |
| 102 | Medium | Binary Tree Level Order Traversal | 102-binary-tree-level-order-traversal.cpp | O(n) | O(n) |
| 103 | Medium | Binary Tree Zigzag Level Order Traversal | 103-binary-tree-zigzag-level-order-traversal.cpp | O(n) | O(n) |
| 104 | Easy | Maximum Depth of Binary Tree | 104-maximum-depth-of-binary-tree.cpp | O(n) | O(log(n)) |
| 105 | Medium | Construct Binary Tree from Preorder and Inorder Traversal | 105-construct-binary-tree-from-preorder-and-inorder-traversal.cpp | O(n) | O(n) |
| 108 | Easy | Convert Sorted Array to Binary Search Tree | 108-convert-sorted-array-to-binary-search-tree.cpp | O(n) | O(n) |
| 111 | Easy | Minimum Depth of Binary Tree | 111-minimum-depth-of-binary-tree.cpp | O(n) | O(log(n)) |
| 112 | Easy | Path Sum | 112-path-sum.cpp | O(n) | O(n) |
| 113 | Medium | Path Sum II | 113-path-sum-ii.cpp | O(n^2) | O(n^2) |
| 116 | Medium | Populating Next Right Pointers in Each Node | 116-populating-next-right-pointers-in-each-node.cpp | O(n) | O(1) |
| 118 | Easy | Pascal's Triangle | 118-pascals-triangle.cpp | O(n^2) | O(n^2) |
| 120 | Medium | Triangle | 120-triangle.cpp | O(n^2) | O(n^2) |
| 121 | Easy | Best Time to Buy and Sell Stock | 121-best-time-to-buy-and-sell-stock.cpp | O(n) | O(1) |
| 122 | Medium | Best Time to Buy and Sell Stock II | 122-best-time-to-buy-and-sell-stock-ii.cpp | O(n) | O(1) |
| 124 | Hard | Binary Tree Maximum Path Sum | 124-binary-tree-maximum-path-sum.cpp | O(n) | O(n) |
| 127 | Hard | Word Ladder | 127-word-ladder.cpp | O(m*n^2) | O(m*n) |
| 136 | Easy | Single Number | 136-single-number.cpp | O(n) | O(1) |
| 139 | Medium | Word Break | 139-word-break.cpp | O(m*n) | O(n) |
| 141 | Easy | Linked List Cycle | 141-linked-list-cycle.cpp | O(n) | O(1) |
| 142 | Medium | Linked List Cycle II | 142-linked-list-cycle-ii.cpp | O(n) | O(1) |
| 144 | Easy | Binary Tree Preorder Traversal | 144-binary-tree-preorder-traversal.cpp | O(n) | O(n) |
| 145 | Easy | Binary Tree Postorder Traversal | 145-binary-tree-postorder-traversal.cpp | O(n) | O(n) |
| 146 | Medium | LRU Cache | 146-lru-cache.cpp | O(1) for { get(key), put(key, value) } | O(n) |
| 153 | Medium | Find Minimum in Rotated Sorted Array | 153-find-minimum-in-rotated-sorted-array.cpp | O(log(n)) | O(log(n)) |
| 155 | Medium | Min Stack | 155-min-stack.cpp | O(1) for { push(x), pop(), top(), getMin() } | O(n) |
| 165 | Medium | Compare Version Numbers | 165-compare-version-numbers.cpp | O(n1+n2) | O(1) |
| 167 | Medium | Two Sum II - Input Array Is Sorted | 167-two-sum-ii-input-array-is-sorted.cpp | O(n) | O(1) |
| 174 | Hard | Dungeon Game | 174-dungeon-game.cpp | O(m*n) | O(m*n) |
| 189 | Medium | Rotate Array | 189-rotate-array.cpp | O(n) | O(1) |
| 190 | Easy | Reverse Bits | 190-reverse-bits.cpp | O(1) | O(1) |
| 191 | Easy | Number of 1 Bits | 191-number-of-1-bits.cpp | O(1) | O(1) |
| 198 | Medium | House Robber | 198-house-robber.cpp | O(n) | O(n) |
| 200 | Medium | Number of Islands | 200-number-of-islands.cpp | O(m*n) | O(m*n) |
| 201 | Medium | Bitwise AND of Numbers Range | 201-bitwise-and-of-numbers-range.cpp | O(log(n)) | O(1) |
| 202 | Easy | Happy Number | 202-happy-number.cpp | O(n) | O(1) |
| 205 | Easy | Isomorphic Strings | 205-isomorphic-strings.cpp | O(n) | O(1) |
| 206 | Easy | Reverse Linked List | 206-reverse-linked-list.cpp | O(n) | O(1) |
| 208 | Medium | Implement Trie (Prefix Tree) | 208-implement-trie-prefix-tree.cpp | O(n) for { insert(word), search(word), startsWith(prefix) } | O(n) |
| 213 | Medium | House Robber II | 213-house-robber-ii.cpp | O(n) | O(n) |
| 215 | Medium | Kth Largest Element in an Array | 215-kth-largest-element-in-an-array.cpp | O(n*log(k)) | O(k) |
| 217 | Easy | Contains Duplicate | 217-contains-duplicate.cpp | O(n) | O(n) |
| 218 | Hard | The Skyline Problem | 218-the-skyline-problem.cpp | O(n*log(n)) | O(n) |
| 221 | Medium | Maximal Square | 221-maximal-square.cpp | O(m*n) | O(m*n) |
| 231 | Easy | Power of Two | 231-power-of-two.cpp | O(1) | O(1) |
| 234 | Easy | Palindrome Linked List | 234-palindrome-linked-list.cpp | O(n) | O(n) |
| 235 | Medium | Lowest Common Ancestor of a Binary Search Tree | 235-lowest-common-ancestor-of-a-binary-search-tree.cpp | O(h) | O(h) or O(1) with tail-call optimization |
| 238 | Medium | Product of Array Except Self | 238-product-of-array-except-self.cpp | O(n) | O(n) |
| 268 | Easy | Missing Number | 268-missing-number.cpp | O(n) | O(1) |
| 278 | Easy | First Bad Version | 278-first-bad-version.cpp | O(log(n)) | O(1) |
| 283 | Easy | Move Zeroes | 283-move-zeroes.cpp | O(n) | O(1) |
| 299 | Medium | Bulls and Cows | 299-bulls-and-cows.cpp | O(n) | O(1) |
| 300 | Medium | Longest Increasing Subsequence | 300-longest-increasing-subsequence.cpp | O(n*log(n)) | O(n) |
| 322 | Medium | Coin Change | 322-coin-change.cpp | O(K*M) | O(K*M) |
| 326 | Easy | Power of Three | 326-power-of-three.cpp | O(1) | O(1) |
| 342 | Easy | Power of Four | 342-power-of-four.cpp | O(1) | O(1) |
| 344 | Easy | Reverse String | 344-reverse-string.cpp | O(n) | O(1) |
| 347 | Medium | Top K Frequent Elements | 347-top-k-frequent-elements.cpp | O(n) | O(n) |
| 349 | Easy | Intersection of Two Arrays | 349-intersection-of-two-arrays.cpp | O(n1+n2) | O(n1+n2) |
| 350 | Easy | Intersection of Two Arrays II | 350-intersection-of-two-arrays-ii.cpp | O(n1+n2) | O(n1+n2) |
| 373 | Medium | Find K Pairs with Smallest Sums | 373-find-k-pairs-with-smallest-sums.cpp | O(k*log(k)) | O(k) |
| 383 | Easy | Ransom Note | 383-ransom-note.cpp | O(m+n) | O(1) |
| 387 | Easy | First Unique Character in a String | 387-first-unique-character-in-a-string.cpp | O(n) | O(1) |
| 392 | Easy | Is Subsequence | 392-is-subsequence.cpp | O(m+n) | O(1) |
| 394 | Medium | Decode String | 394-decode-string.cpp | O(n) | O(n) |
| 409 | Easy | Longest Palindrome | 409-longest-palindrome.cpp | O(n) | O(1) |
| 438 | Medium | Find All Anagrams in a String | 438-find-all-anagrams-in-a-string.cpp | O(m+n) | O(m) |
| 496 | Easy | Next Greater Element I | 496-next-greater-element-i.cpp | O(n1+n2) | O(n1+n2) |
| 503 | Medium | Next Greater Element II | 503-next-greater-element-ii.cpp | O(n) | O(n) |
| 509 | Easy | Fibonacci Number | 509-fibonacci-number.cpp | O(log(n)) | O(log(n)) |
| 525 | Medium | Contiguous Array | 525-contiguous-array.cpp | O(n) | O(n) |
| 542 | Medium | 01 Matrix | 542-01-matrix.cpp | O(m*n) | O(m*n) |
| 543 | Easy | Diameter of Binary Tree | 543-diameter-of-binary-tree.cpp | O(n) | O(n) |
| 557 | Easy | Reverse Words in a String III | 557-reverse-words-in-a-string-iii.cpp | O(n) | O(1) |
| 560 | Medium | Subarray Sum Equals K | 560-subarray-sum-equals-k.cpp | O(n) | O(n) |
| 565 | Medium | Array Nesting | 565-array-nesting.cpp | O(n) | O(n) |
| 566 | Easy | Reshape the Matrix | 566-reshape-the-matrix.cpp | O(m*n) | O(m*n) |
| 567 | Medium | Permutation in String | 567-permutation-in-string.cpp | O(n1+n2) | O(1) |
| 587 | Hard | Erect the Fence | 587-erect-the-fence.cpp | O(n*log(n)) | O(n) |
| 589 | Easy | N-ary Tree Preorder Traversal | 589-n-ary-tree-preorder-traversal.cpp | O(n) | O(n) |
| 617 | Easy | Merge Two Binary Trees | 617-merge-two-binary-trees.cpp | O(n1+n2) | O(n1+n2) |
| 647 | Medium | Palindromic Substrings | 647-palindromic-substrings.cpp | O(n^2) | O(1) |
| 678 | Medium | Valid Parenthesis String | 678-valid-parenthesis-string.cpp | O(n) | O(1) |
| 692 | Medium | Top K Frequent Words | 692-top-k-frequent-words.cpp | O(n*log(k)) | O(n) |
| 695 | Medium | Max Area of Island | 695-max-area-of-island.cpp | O(m*n) | O(m*n) |
| 704 | Easy | Binary Search | 704-binary-search.cpp | O(log(n)) | O(1) |
| 724 | Easy | Find Pivot Index | 724-find-pivot-index.cpp | O(n) | O(1) |
| 733 | Easy | Flood Fill | 733-flood-fill.cpp | O(m*n) | O(m*n) |
| 739 | Medium | Daily Temperatures | 739-daily-temperatures.cpp | O(n) | O(n) |
| 746 | Easy | Min Cost Climbing Stairs | 746-min-cost-climbing-stairs.cpp | O(n) | O(n) |
| 764 | Medium | Largest Plus Sign | 764-largest-plus-sign.cpp | O(n^2) | O(n^2) |
| 784 | Medium | Letter Case Permutation | 784-letter-case-permutation.cpp | O(n*2^n) | O(n*2^n) |
| 844 | Easy | Backspace String Compare | 844-backspace-string-compare.cpp | O(n) | O(1) |
| 848 | Medium | Shifting Letters | 848-shifting-letters.cpp | O(n) | O(n) |
| 865 | Medium | Smallest Subtree with all the Deepest Nodes | 865-smallest-subtree-with-all-the-deepest-nodes.cpp | O(n) | O(n) |
| 876 | Easy | Middle of the Linked List | 876-middle-of-the-linked-list.cpp | O(n) | O(1) |
| 899 | Hard | Orderly Queue | 899-orderly-queue.cpp | O(n^2) | O(n) |
| 917 | Easy | Reverse Only Letters | 917-reverse-only-letters.cpp | O(n) | O(n) |
| 929 | Easy | Unique Email Addresses | 929-unique-email-addresses.cpp | O(n) | O(n) |
| 977 | Easy | Squares of a Sorted Array | 977-squares-of-a-sorted-array.cpp | O(n) | O(n) |
| 978 | Medium | Longest Turbulent Subarray | 978-longest-turbulent-subarray.cpp | O(n) | O(1) |
| 994 | Medium | Rotting Oranges | 994-rotting-oranges.cpp | O(m*n) | O(m*n) |
| 1008 | Medium | Construct Binary Search Tree from Preorder Traversal | 1008-construct-binary-search-tree-from-preorder-traversal.cpp | O(n*log(n)) maybe? | O(n) |
| 1011 | Medium | Capacity To Ship Packages Within D Days | 1011-capacity-to-ship-packages-within-d-days.cpp | O(n*log(sum(W)-max(W))), where W = the weights of packages | O(1) |
| 1046 | Easy | Last Stone Weight | 1046-last-stone-weight.cpp | O(n*log(n)) | O(n) |
| 1137 | Easy | N-th Tribonacci Number | 1137-n-th-tribonacci-number.cpp | O(n) | O(n) |
| 1143 | Medium | Longest Common Subsequence | 1143-longest-common-subsequence.cpp | O(n1*n2) | O(n1*n2) |
| 1189 | Easy | Maximum Number of Balloons | 1189-maximum-number-of-balloons.cpp | O(n) | O(1) |
| 1426 | Easy | Counting Elements | 1426-counting-elements.cpp | O(n) | O(n) |
| 1427 | Easy | Perform String Shifts | 1427-perform-string-shifts.cpp | O(m+n) | O(n) |
| 1428 | Medium | Leftmost Column with at Least a One | 1428-leftmost-column-with-at-least-a-one.cpp | O(r+c) | O(1) |
| 1429 | Medium | First Unique Number | 1429-first-unique-number.cpp | O(1) for { showFirstUnique(), add(value) } | O(n) |
| 1430 | Medium | Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree | 1430-check-if-a-string-is-a-valid-sequence-from-root-to-leaves-path-in-a-binary-tree.cpp | O(n) | O(n) |
| 1475 | Easy | Final Prices With a Special Discount in a Shop | 1475-final-prices-with-a-special-discount-in-a-shop.cpp | O(n) | O(n) |
| 1480 | Easy | Running Sum of 1d Array | 1480-running-sum-of-1d-array.cpp | O(n) | O(n) |
| 1629 | Easy | Slowest Key | 1629-slowest-key.cpp | O(n) | O(1) |
| 1944 | Hard | Number of Visible People in a Queue | 1944-number-of-visible-people-in-a-queue.cpp | O(n) | O(n) |
| 1985 | Medium | Find the Kth Largest Integer in the Array | 1985-find-the-kth-largest-integer-in-the-array.cpp | O(n), on average | O(1) |
| 2487 | Medium | Remove Nodes From Linked List | 2487-remove-nodes-from-linked-list.cpp | O(n) | O(1) |
