LeetCode Single Number I II Python

Single Number

Given an array of integers, every element appears twice except for one. Find that single one.

def singleNumber(self, A):
l = len(A)
if l < 2:
return A[0]
A.sort()
for i in range(0,l-1,2):
if A[i] != A[i+1]:
return A[i]
return A[l-1]

思路：先排序，再找结果。

注意：当A的长度为1时，以及结果为最后一个时（当时没处理最后一个数字为结果导致出现错误，for循环中将最后一个排除了，所以后面要做处理）。

Single Number II

Given an array of integers, every element appears three times except for one. Find that single one.

只要将range里面的步长改为3就行了。