原题地址：https://oj.leetcode.com/problems/pascals-triangle-ii/

题意：

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?

解题思路：思路同上一道题。

class Solution:    # @return a list of integers    def getRow(self, rowIndex):        if rowIndex == 0: return [1]        if rowIndex == 1: return [1, 1]        list = [[] for i in range(rowIndex+1)]        list[0] = [1]        list[1] = [1, 1]        for i in range(2, rowIndex+1):            list[i] = [1 for j in range(i + 1)]            for j in range(1, i):                list[i][j] = list[i - 1][j - 1] + list[i - 1][j]        return list[rowIndex]