# Leetcode 136 - Single number

`Note:`

- Use
`XOR`

to find the extra.

`Question:`

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 = [4,1,2,1,2] |

`Code:`

1 | /** |