Single Number

Given an integer array nums, every element appears twice except for one. Return the element that appears only once.

Function signature

func SingleNumber(nums []int) int

Example

nums = [2,2,1]
output = 1

Constraints

• 1 <= len(nums) <= 200000
• -1_000_000_000 <= nums[i] <= 1_000_000_000

Notes

• Aim for O(n) time and O(1) extra space.
• XOR cancels paired values.