Pascal's Triangle II

Total Accepted: 105799 Total Submissions: 297504 Difficulty: Easy Contributors: Admin 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?

思路就是从头到尾数一遍，找到该层

class Solution(object): def getRow(self, rowIndex): """ :type rowIndex: int :rtype: List[int] """ tmp = [1] i = 0 while(i != rowIndex): tmp = map(lambda x, y: x+y, tmp+[0], [0]+tmp) i += 1 return tmp