AlgoLounge

Single Number

easy

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.

Examples

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

Constraints

  • 1 <= nums.length <= 3 * 10⁴
  • -3 * 10⁴ <= nums[i] <= 3 * 10⁴
  • Each element in the array appears twice except for one element which appears only once.
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List of test cases (8)
Case 1
nums = [2,2,1]
Case 2
nums = [4,1,2,1,2]
Case 3
nums = [1]
Case 4
nums = [7,6,6,7,8]
Case 5
nums = [3,2,3]
Case 6
nums = [-1,-1,-2]
Case 7
nums = [0,1,0]
Case 8
nums = [100,200,100,200,300]