Pascal's Triangle II

Given an indexk, return thekthrow of the Pascal's triangle.

For example, givenk= 3, Return[1,3,3,1].

1. 用了pascals triangle I的方法，最后返回最后一行，但是用了额外的空间，另外注意两题一个numberrow，一个是rowindex

class Solution(object):
    def getRow(self, rowIndex):
        """
        :type rowIndex: int
        :rtype: List[int]
        """
        result = [[1]*(i+1) for i in xrange(rowIndex+1)]
        if rowIndex == 0:
            return [1]

        for i in xrange(1, rowIndex+1):
            for j in xrange(1, i):
                result[i][j] = result[i-1][j-1] + result[i-1][j]
        return result[rowIndex]

2.