C Program to Find Sum of First N Natural Numbers

This C program finds the sum of the first N natural numbers, where N is entered by the user. The program then calculates the sum using a loop and prints it to the screen.

Problem Statement

Write a C program that finds the sum of the first N natural numbers, where N is entered by the user. The program should prompt the user to enter the value of N, calculate the sum using a loop, and print it to the screen.

Solution

#include <stdio.h>

int main() {
   int n, i, sum = 0;

   // Get the value of n from user
   printf("Enter the value of n: ");
   scanf("%d", &n);

   // Calculate the sum using a loop
   for (i = 1; i <= n; i++) {
      sum += i;
   }

   // Print the sum to the screen
   printf("The sum of first %d natural numbers is %d", n, sum);

   return 0;
}

Output

Explanation

The program starts by declaring variables to hold the value of N (n), a loop counter (i), and the sum of the first N natural numbers (sum).

The program then prompts the user to enter the value of N, and stores the value in the n variable.

Next, the program calculates the sum of the first N natural numbers using a for loop with i as the loop counter. For each iteration of the loop, the program adds i to the sum variable.

After the loop, the program prints the sum of the first N natural numbers to the screen using printf() function.

Finally, the program exits.

Conclusion

This C program demonstrates how to find the sum of the first N natural numbers. It prompts the user to enter the value of N, calculates the sum using a loop, and prints it to the screen.