Factorial Program In C

Factorial Program In C

Factorial Program in C: Factorial of n is the product of all positive descending integers. Before going to see factorial program in c we will see what is the factorial means. lets see what is concept of factorial number-

What is a Factorial Number

factorial number is nothing but the multiplication of all smaller  numbers of that particular number including itself. for better understanding see the following example-

if we want to ascertain 5!(factorial of 5) then,

5!=5*4*3*2*1

means 5!=120.(factorial of 5 is 120)

(note: factorial is denoted by '!' mark.)

we can write factorial program using many ways ,but here we will see the programs using for loop,while loop and c factorial program using function recursion.

C factorial Program : Using For loop

#include<stdio.h>

void main() 

{ 

 int num,i;

int fact=1; 

 printf("Enter a number To Find Out Factorial: "); 

  scanf("%d",&num); 

    for(i=1;i<=num;i++){ 

      fact=fact*i; 

  } 

  printf("The Factorial of %d is: %d",num,fact); 

getch();

} 

Output:



Enter a number To Find Out Factorial: 4

The Factorial of 5 is: 24

C Factorial Program: Using While Loop

 

#include<stdio.h>

# include<conio.h>

void main()

{

 int num,fact=1,copyno=0;

 printf("Enter Number To Findout Factorial:");

 scanf("%d",&num);

 copyno=num;

 while(num>0)

 {

  fact=fact*num;

  num--;

 }

 printf("Factorial of %d is:%d",copyno,fact);

 getch();

}

Output:

Enter Number To Findout Factorial:3

Factorial of 3 is :6

C Factorial Program : Using Function Recursion

#include<stdio.h>



long fact(int n)

{

  if (num == 0)

    return 1;

  else

    return(num * factorial(num-1));

}

 

void main()

{

  int num;

  long factNum;

  printf("Enter a number To Find Out Factorial: ");

  scanf("%d", &num); 

 

  factNum = fact(num);

  printf("Factorial of %d is %ld\n", num, factNum);

  getch();

} 

Output:

Enter a number To Find Out Factorial: 5

Factorial of 5 is: 120