119. Pascal's Triangle II(easy amazon)

//https://leetcode.com/problems/pascals-triangle-ii/description/
//blog: https://www.cnblogs.com/stiles/p/leetcode119.html
class Solution {
    public List<Integer> getRow(int rowIndex) {
        List<Integer> res = new ArrayList<>();
        res.add(1);
        for(int i = 1; i<=rowIndex; i++){
            int temp = res.get(0);
            for(int j = 1; j<i; j++){
                int k = res.get(j);
                res.set(j, k+temp);
                temp = k;
            }
            res.add(1);
        }
     return res; 
    }
}