programming-challenges/challenges/single-number

single-number

Created by @theoludwig on 21 August 2023.

Instructions

Given a non-empty array of integers, 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.

Constraints

• 1 <= numbers.length <= 3 \times 10^4

• -3 \times 10^4 <= numbers[index] <= 3 \times 10^4

• Each element in the array appears twice except for one element which appears only once.

Source

LeetCode - Single Number

Examples

See the test folder for examples of input/output.

Example 1

Input

4
1
2
1
2

Output

4