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?

题目大意：给定一个数组，只有一个数出现过1次，其余均出现过2次，找出出现过一次的数

题目难度：Medium

/**
 * Created by gzdaijie on 16/6/15
 */
public class Solution {
    public int singleNumber(int[] nums) {
        int result = 0;
        for (int i = 0; i < nums.length; i++) {
            result ^= nums[i];
        }
        return result;
    }
}