In this post, we will learn how to find the sum of natural numbers using recursion in C Programming language.
Natural Numbers are a part of the number system which includes all the positive integers from 1 till infinity and are also used for counting. For example: 1, 2, 3, 4, 5, 6, 7, . . . , and so on.
In the program, we will calculate the sum of natural numbers using recursion. For example: The Sum of the first 5 Natural Numbers is (1 + 2 + 3+ 4 + 5) = 15.
So, without further ado, let’s begin this tutorial.
C Program to Find the Sum of Natural Numbers using Recursion
// C Program To Find the Sum of Natural Numbers Using Recursion
#include <stdio.h>
int Sum(int n);
int main(){
int num;
// Asking for Input
printf("Enter a number: ");
scanf("%d", &num);
printf("Sum of %d Natural Numbers is %d.", num, Sum(num));
return 0;
}
int Sum(int n){
if (n != 0)
return n + Sum(n - 1);
else
return n;
}
Output
Enter a number: 7
Sum of 7 Natural Numbers is 28.
How Does This Program Work ?
int num;
In this program, we have declared an int data type variable named as num.
// Asking for Input
printf("Enter a number: ");
scanf("%d", &num);
Then, the user is asked to enter a number. The value of this number will get stored in num named variable.
int Sum(int n){
if (n != 0)
return n + Sum(n - 1);
else
return n;
}
Here, we have defined a custom function named Sum which will calculate and returns the sum of natural numbers.
Suppose, the user enters the number 5.
Initially, the function Sum() is called from main() with 5 passed as an argument. Then, the number 5 is added to the result of Sum(4).
In the next call, 4 is added to the result of Sum(3). This process continues until n = 0.
When n = 0, our recursive calls terminate and this returns the sum of integers to the main() function.
Conclusion
I hope after going through this post, you understand how to find the sum of natural numbers using recursion in C Programming language.
If you have any doubt regarding the program, feel free to contact us in the comment section. We will be delighted to help you.
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