Programs that use recursive function to find the factorial of a given integer

Description:

Factorial of a number is nothing but the multiplication of numbers from a given number to 1

Algorithm: main program

Step 1:  start

Step 2: read n

Step 3: call sub program as f=fact(n)

Step 4: print f value

Step 5: stop

 Sub program:

Step 1: initialize the f

Step 2: if n= = 0 or n == 1 return 1 to main program if not goto step 3

Step 3: return n*fact(n-1) to main program

 

Program:

#include<stdio.h>

#include<conio.h>

int fact(int n)

 {

            int f;

            if((n==0)||(n==1))  // check the condition for the  n value

             return(n);

            else

             f=n*fact(n-1);   //calculate the factorial of n

             return(f);

 }

void main()

{

            int n;

            clrscr();

            printf("enter the  number :");

            scanf("%d",&n);

             printf("factoria of number%d",fact(n));

            getch();

}

Output:

1. Enter the number : 5

     Factorial of number: 120

2. Enter the number : 3

     Factorial of number: 6

3. Enter the number : 9

    Factorial of number: -30336

Conclusion: the program is error free

VIVA QUESATIONS:

1)      What is the meaning of factorial  number?

Ans : Factorial of a number is nothing but the multiplication of numbers from a given 

          number to 1

2)      What is the meaning of recusive function ?

Ans:  A function call it self is called recursive function

3)      define library functions ?

Ans: The functions have already been written, compiled and placed in libraries and are   

         called library functions.

4)      Define formal parameters ?

Ans:    Formal parameters  are the parameters given in the function declaration ans  

           function definition.