136. Single Number

Leetcode: 136. Single Number
Given a non-empty 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?

Example 1:

Input: [2,2,1]
Output: 1

Example 2:

Input: [4,1,2,1,2]
Output: 4

Solution:

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