Single Number — Easy Coding Interview 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

Input: nums = [2,2,1]

Output: 1

Constraints

• 1 ≤ nums.length ≤ 3 * 10⁴
• Every element appears twice except one

Topics & Companies

Topics: bit-manipulation, arrays

Asked by: Amazon, Google, Meta, Microsoft, Apple

Optimal Solution Complexity

Time complexity: O(n). Space complexity: O(1).

Practice more

• All DSA Problems
• DSA Patterns