LeetCode_Pascal's Triangle II

Given an index k, return the kth 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> result(rowIndex+);
       result[] = ;

        int temp1 = , temp2 = ;
        for(int i = ; i<= rowIndex ; i++)
          for(int j = ; j< i+; j++){
            temp2 = result[j];
            if(j ==  || j == i)
                result[j] = ;
             else
                 result[j] += temp1 ;
            temp1 = temp2;
          }

          return result;
    }
};