leetcode--136--Single Number

题目来源：

https://leetcode.com/problems/single-number/discuss/

转载请注明出处：

http://blog.youkuaiyun.com/believexfr/article/details/78011958

题目：

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?

参考答案：

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

说明：

偶数个相同的数异或运算结果是0，异或运算满足交换律

a xor b xor c  =  a xor c xor b