Recursion Using - C
  
 Source Code
  

  
#include<stdio.h>

int factorial(int n);

void main() {
    int n;
    printf("Enter a number: ");
    scanf("%d", &n);
    printf("Factorial of %d is %d",n,factorial(n));
}

int factorial(int n) {
   if(n==0)
	   	return 1;
	else {
		return n * factorial(n-1);
	}
}

Enter a number: 5
Factorial of 5 is 120

  
Iteration Using - C
  
 Source Code
  

  
#include<stdio.h>

int factorial(int n);

void main() {
    int n;
    printf("Enter a number: ");
    scanf("%d", &n);
    printf("Factorial of %d is %d",n,factorial(n));
}

int factorial(int n) {
   int i, fact=1;
   
   if(n==0)
   		return 1;
   	else {
   		for(i=1; i <= n; i++){
   			fact *= i;		
		}
		return fact;
	}
}
 
  

Enter a number: 0
Factorial of 0 is 1

        
Rescursion Using - C++
        
 Source Code
        

        
#include<iostream>
using namespace std;

int factorial(int n);

int main() {
    int n;
    cout<< "Enter a number: ";
    cin>> n;
    cout<< "Factorial of "<< n<< " is "<< factorial(n); 
    return 0;
}

int factorial(int n) {
   if(n==0)
	   	return 1;
	else {
		return n * factorial(n-1);
	}
} 

Enter a number: 6
Factorial of 6 is 720

  
Iteration Using - C++
  
 Source Code
  

  
#include<iostream>
using namespace std;

int factorial(int n);

int main() {
    int n;
    cout<< "Enter a number: ";
    cin>> n;
    cout<< "Factorial of "<< n<< " is "<< factorial(n); 
    return 0;
}

int factorial(int n) {
	int fact=1;
	
    if(n==0)
	   	return 1;
	else {
		for(int i=n; i > 0; i--){
			fact *= i;
		}	
		return fact;
	}
}

Enter a number: 4
Factorial of 4 is 24