136. Single Number

Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

You must implement a solution with a linear runtime complexity and use only constant extra space.

Example 1:

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

Example 2:

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

Example 3:

Input: nums = [1]
Output: 1

public int singleNumber(int[] nums) {
    int result = 0;
    for (int i = 0; i < nums.length; i++) {
        result ^= nums[i];
    }
    return result;
}