求1+2+3+...+n
求1+2+3+...+n
http://www.nowcoder.com/questionTerminal/7a0da8fc483247ff8800059e12d7caf1
一行代码简便解法,直接递归短路代替if语句,当n为0或者负数时,自动忽略之后的递归
# -*- coding:utf-8 -*- class Solution: def Sum_Solution(self, n): # write code here return n and ( n + self.Sum_Solution(n-1) )