Single Number Leetcode Solution

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.

Table of Contents

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.