LeetCode119. Pascal's Triangle II

Description

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

For example, given k = 3,

Return [1,3,3,1].

my program

class Solution {
public:
    vector<int> getRow(int rowIndex) {
        vector<int> res = {1};
        for(int i = 1; i<=rowIndex; i++)
        {
            res.push_back(0);
            for(int j = res.size(); j>0; j--)
            {
                res[j] += res[j-1];
            }
        }
        return res;
    }
};

34 / 34 test cases passed.

Status: Accepted

Runtime: 0 ms

other methods

vector<int> getRow(int rowIndex) {
    vector<int> ans(rowIndex+1,1);
    int small = rowIndex/2;
    long comb = 1;
    int j = 1;
    for (int i=rowIndex; i>=small; i--){
        comb *= i;
        comb /= j;
        j ++;
        ans[i-1] = (int)comb;
        ans[j-1] = (int)comb;
    }
    return ans;
}