In this post, we are going to solve the Single Number Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.

Problem
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 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.
Now, let’s see the leetcode solution of Single Number Leetcode Solution.
Single Number Leetcode Solution in Python
class Solution: def singleNumber(self, nums: List[int]) -> int: return functools.reduce(lambda x, y: x ^ y, nums, 0)
Single Number Leetcode Solution in CPP
class Solution { public: int singleNumber(vector<int>& nums) { int ans = 0; for (const int num : nums) ans ^= num; return ans; } };
Single Number Leetcode Solution in Java
class Solution { public int singleNumber(int[] nums) { int ans = 0; for (final int num : nums) ans ^= num; return ans; } }
Note: This problem Single Number is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purpose.