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/*

Author: Annie Kim, anniekim.pku@gmail.com

Date: Apr 16, 2013

Problem: Pascal's Triangle II

Difficulty: Easy

Source: http://leetcode.com/onlinejudge#question_119

Notes:

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?

Solution: from back to forth...

*/

public class Solution {

public List<Integer> getRow(int rowIndex) {

List<Integer> res = new ArrayList<Integer>();

res.add(1);

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

for (int j = i - 1; j >= 1; --j) {

res.set(j,res.get(j) + res.get(j-1));

}

res.add(1);

}

return res;

}

}