/* */ class Solution { public: vector<int> findElement(vector<vector<int> > mat, int n, int m, int x) { vector<int> ans; if(n == 0 || m == 0) return ans; int row = 0, col = m-1; while( row < n && col >= 0){ if(mat[row][col] < x) row++; else if(mat[row][col] > x) col--; else { ans.push_back(row); ans.push_back(col); return ans; } } return ans; } };