136. 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?

Similar: 

137. Single Number II

260. Single Number III

268. Missing Number

287. Find the Duplicate Number

1 public class Solution {
2     public int singleNumber(int[] nums) {
3         int ret = nums[0];
4         for (int i = 1; i < nums.length; i++) {
5             ret ^= nums[i];
6         }
7         return ret;
8     }
9 }

136. Single Number

原文：http://www.cnblogs.com/joycelee/p/5407706.html