c-program to find the sum of the natural number by recursion. | c-programming languages

program to calculate the sum of  the natural number by using recursion.

In this program we ,we now calculate the sum of natural number using recursion in c-program, taking  input  positive integer from the user.
Recursion means function calling itself is called recursion.
suppose 15 is passed as an argument  to the function fun() ,from the main method . In the fun() function,
subsequently until "if" statement  returns the false value ,then the value decrease by one in every step and   we added fun(num-1) to num. the statement is doing it until num value is 0. if the num values is 0 ,then the else block gets execute and o is return
Therefore ,function return the value form which where function is call in the main()function.

#include<stdio.h>
#include<stdio.h>
int fun(int num);
void main()
{
   int n,sum=0;
   printf("enter the number\n");
   scanf("%d",&n);
   sum=fun(n);
   printf("the sum of the number is %d",sum);
   getch();
}
int fun(int num)
{
   if(num==1)
         return(1);
   else
         return(num+fun(num-1));
}

Output:- enter the number:- 15

           the sum of the number is 120.

For more c-programming example:-

1.c-program to calculate the sum of the natural number by using recursion