118. Pascal's Triangle.cpp

 

class Solution {
public:
    vector<vector<int>> generate(int numRows) {
        vector<vector<int>>res;
        for(int i =1; i<=numRows;i++){
            vector<int>tmp;
            
            for(int j =0; j<i;j++){
                if(j==0 || j==i-1) tmp.push_back(1);
                else tmp.push_back(res[i-2][j-1]+res[i-2][j]);
            }
            
            res.push_back(tmp);
        }
        return res;
    }
};