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?

解题思路

亦或运算。

实现代码

// Runtime: 1 ms
public class Solution {
    public int singleNumber(int[] nums) {
        int single = nums[0];
        for (int i = 1; i < nums.length; i++) {
            single ^= nums[i];
        }

        return single;
    }
}