leetcode -- Pascal's Triangle -- 简单

https://leetcode.com/problems/pascals-triangle/

就是几个循环而已。很简单

class Solution(object):    def generate(self, numRows):        """        :type numRows: int        :rtype: List[List[int]]        """        if numRows == 0:            return []        elif numRows == 1:            return [[1]]        elif numRows == 2:            return [[1],[1,1]]        reslist = [[1],[1,1]]        for i in xrange(2, numRows):            mylist = [1]            for j in xrange(1, i):                tmp = sum(reslist[i - 1][j - 1 : j + 1])                mylist.append(tmp)            mylist.append(1)            reslist.append(mylist)        return reslist