RECURSIVE FUNCTION

Write a recursive function to calculate the factorial of the number.

When a function call itself or when a function call to a second function and in the function definition of 2^nd function again a function call statement for the first function is encountered it is known as recursion and this function is known as recursive function.

Let’s do the program: -

#include<stdio.h>

int factorial (int);

void main()

{

int a,b;

clrscr();

printf("\n enter a no=");

scanf("%d",&a);

b=factorial(a);

printf("\n factorial is =%d",b);

getch();

}

int factorial (int a)

{

if(a==0)

return 1;

else

return(a*factorial(a-1));

}

Dry run: -

a=5 (say)

return

5* factorial (4)

a=4

5*4* factorial (3)

a=3

5*4*3* factorial (2)

a=2

5*4*3*2*factorial (1)

a=1

5*4*3*2*1*factorial (o)

a==0 (true)

return 1

5*4*3*2*1*1= 120

Factorial is = 120.