LeetCode 119. Pascal's Triangle II

119. Pascal’s Triangle II

Given an index k, return the kth row of the Pascal’s triangle.

class Solution {
public:
    vector<int> getRow(int rowIndex) {
         vector<int> ANS;
         ANS.push_back(1);
         long long ans = 1, a = rowIndex, b = 1;
         while(a >=1 ) 
         {
             ans *= a;
             ans /= b;
             a--; b++;
             ANS.push_back((int)ans);
         }
         return ANS;
    }
};