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?

描述

一组数，除了一个数外，其余数都出现 2 次，找出那个数

分析

使用异或的方式，A ^ A = 0，A ^ A ^ B = B

代码

public class Solution {
    public int singleNumber(int[] nums) {

        int num = 0, len = nums.length;

        for (int i = 0; i < len; i++) {
            num ^= nums[i];
        }

        return num;
    }
}