LeetCode 136 - Single Number Problem

Problem Statement

Given a non-empty array of integers, every element appears twice except for one. Find that single one.


Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Example 1:

Input: [2,2,1]
Output: 1

Example 2:

Input: [4,1,2,1,2]
Output: 4


class Solution: def singleNumber(self, nums: List[int]) -> int: result = 0 for num in nums: result ^= num return result