|357|[Count Numbers with Unique Digits](https://leetcode.com/problems/count-numbers-with-unique-digits/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_357.java)| O(?)|O(?)| Medium|

|356|[Line Reflection](https://leetcode.com/problems/line-reflection/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_356.java)| O(n)|O(n) | Medium| HashSet

|355|[Design Twitter](https://leetcode.com/problems/design-twitter/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_355.java)| O(n)|O(n) | Medium| Design, HashMap, Heap

|354|[Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_354.java)| O(nlogn)|O(1) | Hard| DP, Binary Search

|353|[Design Snake Game](https://leetcode.com/problems/design-snake-game/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_353.java)| O(?)|O(?)| Medium|

|352|[Data Stream as Disjoint Intervals](https://leetcode.com/problems/data-stream-as-disjoint-intervals/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_352.java)| O(logn)|O(n) | Hard| TreeMap

|351|[Android Unlock Patterns](https://leetcode.com/problems/android-unlock-patterns/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_351.java)| O(?)|O(?)| Medium|

packagecom.fishercoder.solutions;

importjava.util.Arrays;

publicclass_354 {

publicintmaxEnvelopes(int[][]envelopes) {

if (envelopes ==null ||envelopes.length ==0

||envelopes[0].length ==0 ||envelopes[0].length !=2) {

return0;

}

Arrays.sort(envelopes, (int[]a,int[]b) ->

{

if (a[0] ==b[0])returnb[1] -a[1];

elsereturna[0] -b[0];

}

);

int[]dp =newint[envelopes.length];

intlen =0;

for (int[]envelope :envelopes) {

intindex =Arrays.binarySearch(dp,0,len,envelope[1]);

if (index <0) {

index = -(index+1);

}

dp[index] =envelope[1];

if (index ==len) {

len++;

}

}

returnlen;

}

}