Single Number

Leetcode Problem 136: Single Number

Problem Summary

Given a non-empty array of integers where every element appears exactly twice except for one element that appears only once, find and return that single element.

Your solution must use linear time and constant extra space.

Constraints:

• The array has between 1 and 30,000 elements.
• Values are in the range [-30,000, 30,000].
• Every element appears twice except for exactly one element.

Techniques

• Array
• Bit Manipulation

Solution

const singleNumber = (nums: number[]) => nums.reduce((accumulator, current) => accumulator ^ current)