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+1);

       result[0] = 1;

      

        int temp1 = 0, temp2 = 0;

        for(int i = 1; i<= rowIndex ; i++)

          for(int j = 0; j< i+1; j++){

            temp2 = result[j]; 

            if(j == 0 || j == i)

                result[j] = 1;

             else 

                 result[j] += temp1 ;    

            temp1 = temp2;  

          }

          

          return result;

    }

};