## LeetCode 672. Bulb Switcher II

 123456 int flipLights(int n, int m) {     if(m==0||n==0)return 1;     if(n==1)return 2;     if(n==2){         if(m==1){             return 3;[......]

## LeetCode 554. Brick Wall

 123456789 static auto x = []() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     return 0; }(); class Solution { public:     int leastBrick[......]

## LeetCode 881. Boats to Save People

 12345 int cmp(void* a,void* b){     return *(int*)a-*(int*)b; } int numRescueBoats(int* people, int peopleSize, int limit) {     qsort(people, peopleS[......]

## LeetCode 898. Bitwise ORs of Subarrays

 1234567891011 static auto x = []() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     return 0; }(); class Solution { public:     int subarr[......]

## LeetCode 201. Bitwise AND of Numbers Range

 12 int rangeBitwiseAnd(int m, int n) {      return m==n?m:(rangeBitwiseAnd(m>>1,n>>1)[......]

## LeetCode 145. Binary Tree Postorder Traversal

 12345678 static auto x = []() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     return 0; }(); /**  * Definition for a binary tree node.[......]

## LeetCode 103. Binary Tree Zigzag Level Order Traversal

 123456789 static auto x = []() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     return 0; }(); /**  * Definition for a binary tree node.[......]

## LeetCode 823. Binary Trees With Factors

 123456 int cmp(const void * a,const void * b) {     return (*(int*)a-*(int*)b); } int numFactoredBinaryTrees(int* A, int ASize) {     if(ASize[......]