【leetcode】119. Pascal's Triangle II【java】

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?

public class Solution {    public List<Integer> getRow(int rowIndex) {        List<Integer> result = new ArrayList<Integer>();        if (rowIndex < 0) {            return result;        }        for (int i = 0; i < rowIndex + 1; i++) {            result.add(0, 1);            for (int j = 1; j < result.size() - 1; j++){                result.set(j, result.get(j) + result.get(j + 1));            }        }        return result;    }}