Single Number

　　Given an 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?

　　线性时间完成，不花费多余空间，问题特殊，异或运算就解决了。

public class Solution {
    public int singleNumber(int[] nums) {
        int result = 0;
        for(int num: nums)
        {
            result^=num;
        }
        return result;
    }
}