Sword finger offer 64. find 1+2+... +n, logical operator short circuit effect

The finger of the sword Offer 64. seek 1+2+…+nhttps://leetcode.cn/problems/qiu-12n-lcof/

Ideas for solving problems. See

Interview questions 64. seek 1 + 2 + … + n（ Logic symbol short circuit , Clear illustration ） - seek 1+2+…+n - Power button （LeetCode）https://leetcode.cn/problems/qiu-12n-lcof/solution/mian-shi-ti-64-qiu-1-2-nluo-ji-fu-duan-lu-qing-xi-/ There are three common logical operators , namely “ And and ”,“ or or ”,“ Not not ” ; And it has important short-circuit effect , As shown below ：

if(A and B)   if A by false , be B Your judgment will not be executed （ Short circuit ）, Direct determination A and B by false

if(A or B)   if A by true , be B Your judgment will not be executed （ Short circuit ）, Direct determination A or B by true

 

class Solution:
    def sumNums(self, n):
        def digui(n):
            n>1 and digui(n-1)
            self.res+=n
        self.res=0
        digui(n)
        return self.res
a=Solution()
print(a.sumNums(3))
print(a.sumNums(9))