[LeetCode 136] Single Number

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

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

Diffculty
Easy

Similar Problems

Analysis

class Solution { public: int singleNumber(vector& A) { int res = 0; for(int i = 0; i < (int)A.size(); ++i){ res ^= A[i]; } return res; } };