In this post, we are going to solve the 268. Missing Number problem of Leetcode. This problem 268. Missing Number is a Leetcode easy level problem. Let’s see the code, 268. Missing Number – Leetcode Solution.

Problem

Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.

Example 1 :

Input: nums = [3,0,1]
Output: 2
Explanation: n = 3 since there are 3 numbers, so all numbers are in the range [0,3]. 2 is the missing number in the range since it does not appear in nums.

Example 2 :

Input: nums = [0,1]
Output: 2
Explanation: n = 2 since there are 2 numbers, so all numbers are in the range [0,2]. 2 is the missing number in the range since it does not appear in nums.

Example 3 :

Input: nums = [9,6,4,2,3,5,7,0,1]
Output: 8
Explanation: n = 9 since there are 9 numbers, so all numbers are in the range [0,9]. 8 is the missing number in the range since it does not appear in nums.

Constraints

• n == nums.length
• 1 <= n <= 104
• 0 <= nums[i] <= n
• All the numbers of nums are unique.

Now, let’s see the code of 268. Missing Number – Leetcode Solution.

Missing Number – Leetcode Solution

268. Missing Number – Solution in Java

class Solution {
    public int missingNumber(int[] nums) {
        int n = nums.length;
        int ans=0;
        for(int i=0;i<n;i++){
            ans ^= nums[i] ^ (i+1);
        }
        return ans;
    }
}

268. Missing Number – Solution in C++

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        int result = nums.size();
        int i=0;
        
        for(int num:nums){
            result ^= num;
            result ^= i;
            i++;
        }
        
        return result;
    }
};

268. Missing Number – Solution in Python

def missingNumber(self, nums: List[int]) -> int:
    
    result = 0
    
    for counter,value in enumerate(nums):
        
        result ^= counter+1 
        result ^= value 
        
    return result

Note: This problem 268. Missing Number is generated by Leetcode but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.