# Algorithm Puzzles: Single Number

Algorithm Puzzles ~~everyday~~ ~~every week~~ sometimes: Single Number

## Puzzle

Puzzle from leetcode:

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

## Solution

1 | class Solution { |

T.C.: `O(N)`

S.C.: `O(1)`