LeetCode --- Pascal's Triangle

 1 class Solution {  2 public:  3     vector<vector<int> > generate(int numRows) {  4         vector<vector<int> > ans(numRows);  5         for (int i = 0; i < numRows; i++) {  6             ans[i].push_back(1);  7             for (int j = 1; j < i; j++) {  8                 ans[i].push_back(ans[i-1][j-1] + ans[i-1][j]);  9  } 10             if (i > 0) { 11                 ans[i].push_back(1); 12  } 13  } 14         

15         return ans; 16  } 17 };