```
// autho : s2003zy
// weibo : weibo.com/songzy982
// blog : s2003zy.com
class Solution {
public:
vector<vector<int>> generate(int numRows) {
vector<vector<int>> res = {};
for (int i = 0; i < numRows; i++) {
res.push_back(vector<int>(i + 1, 1));
for(int j = 1; j < i; j++) {
res[i][j] = (res[i - 1][j] + res[i - 1][j - 1]);
}
}
return res;
}
};
```