[leetcode] Pascal's Triangle II

Given an index k, return the k^th row of the Pascal's triangle.

For example, given k = 3,
Return [1,3,3,1].

Note:
Could you optimize your algorithm to use only O(k) extra space?

class Solution {
public:
    vector<int> getRow(int rowIndex) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<int> cur;
        cur.push_back(1);
        for(int i=1 ; i<=rowIndex ; i++){
            vector<int> temp;
            temp.push_back(1);
            for(int j=1 ; j<i ; j++)
                temp.push_back(cur[j-1]+cur[j]);
            temp.push_back(1);
            cur=temp;
        }
        return cur;
    }
};