Find the Missing Number Using – python, java and c

Python

def find_missing_number(nums):
    n = len(nums) + 1
    total_sum = (n * (n + 1)) // 2
    actual_sum = sum(nums)
    return total_sum - actual_sum

input_nums = [1, 2, 4, 6, 3, 7, 8]
missing_number = find_missing_number(input_nums)
print("The missing number is:", missing_number)

Java

public class MissingNumber {
    public static int findMissingNumber(int[] nums) {
        int n = nums.length + 1;
        int totalSum = (n * (n + 1)) / 2;
        int actualSum = 0;
        for (int num : nums) {
            actualSum += num;
        }
        return totalSum - actualSum;
    }

    public static void main(String[] args) {
        int[] inputNums = {1, 2, 4, 6, 3, 7, 8};
        int missingNumber = findMissingNumber(inputNums);
        System.out.println("The missing number is: " + missingNumber);
    }
}

Using C

#include <stdio.h>

int findMissingNumber(int nums[], int n) {
    int totalSum = (n * (n + 1)) / 2;
    int actualSum = 0;
    for (int i = 0; i < n - 1; i++) {
        actualSum += nums[i];
    }
    return totalSum - actualSum;
}

int main() {
    int inputNums[] = {1, 2, 4, 6, 3, 7, 8};
    int n = sizeof(inputNums) / sizeof(inputNums[0]);
    int missingNumber = findMissingNumber(inputNums, n);
    printf("The missing number is: %d\n", missingNumber);
    return 0;
}