Leetcode 109

//这种也是空间复杂度为O(K)的解法，就是边界有点难写
class Solution {
public:
    vector<int> getRow(int rowIndex) {
        vector<int> res;
        res.push_back();
        if(rowIndex == ) return res;
        res.push_back();
        if(rowIndex == ) return res;
        for(int i=;i <= rowIndex;i++){
            res.push_back();
            int a = res[];
            int b = res[];
            for(int j=;j < i;j++){
                res[j] = a+b;
                a = b;
                b = res[j+];
            }
            res[i] = ;
        }
        return res;
    }
};