# Single Number Leetcode Solution

#### ByBrokenprogrammers

Dec 12, 2022

Hello Programmers, In this post you will know how to solve the Single Number Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.

One more thing to add, don’t directly look for the solutions, first try to solve the problems of Leetcode by yourself. If you find any difficulty after trying several times, then you can look for solutions.

## 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.

### Single Number Leetcode Solutions in Python

```class Solution:
def singleNumber(self, nums: List[int]) -> int:
return functools.reduce(lambda x, y: x ^ y, nums, 0)```

### Single Number Leetcode Solutionsin CPP

```class Solution {
public:
int singleNumber(vector<int>& nums) {
int ans = 0;
for (const int num : nums)
ans ^= num;
return ans;
}
};```

### Single Number Leetcode Solutions 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 BrokenProgrammers. This tutorial is only for Educational and Learning purposes.