solution:
std:
class Solution { public: bool Find(int target, vector<vector<int> > array) { int n = array.size(); int m = array[0].size(); int i = 0 ,j = m - 1; while(i < n && j >= 0){ if(array[i][j] == target) return true ; if(array[i][j] > target) j--; else i++; } return false; } };