class Solution { public: vector<vector<int>> generate(int numRows) { vector<vector<int>> result; vector<int> res; for(int i = 1;i <= numRows;i++){ for(int j = 1;j <= i;j++) res.push_back(1); result.push_back(res); res.clear(); } if(numRows <= 2) return result; for(int i = 2;i < numRows;i++){ for(int j = 1;j < i;j++){ result[i][j] = result[i-1][j-1] + result[i-1][j]; } } return result; } };
https://leetcode.com/problems/pascals-triangle/discuss/166279/cpp-beats-1002018.9.3(with-annotation)