Pascal's Triangle

Given numRows, generate the first numRows of Pascal’s triangle.

For example, given numRows = 5, Return

[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ]

自己没有想到很好的解法，看了solution，被其代码惊呆了，写的很好。

class Solution(object): def generate(self, numRows): """ :type numRows: int :rtype: List[List[int]] """ if numRows == 0: return [] res = [[1]] for i in range(1, numRows): res += [map(lambda x, y: x+y, res[-1] + [0], [0] + res[-1])] return res