Exercises 1

Factorial

Factorial is a mathematical operation defined by


n! = n * (n-1) * (n-2) * ... * 1

Write a recursive function to calculate factorial of any natural number.

Tip: Factorial is defined by recursion by


n! = n * (n-1)!

Please note: 0-factorial equals 1 pr. definition.

First - sketch your function on paper.
Next – implement a program to test it.

Solution:

Input n (integer):

Result :

Code:

Languages:


//Javascript function
function FactorialRecusive(n){
	if(n===1){
		return 1;
	}else{
		return n*FactorialRecusive(n-1);
	}
}	
function Factorial(n){
	var total = n;
	while(n>1){
		n--;
		total *= n;
	}
	return total;
}


//Javascript Object Oriented Static Class Method
function AI(){}
AI.factorialRecusive = function(n){
	if(n===1){
		return 1;
	}else{
		return n*AI.factorialRecusive(n-1);
	}
}
AI.factorial = function(n){
	var total = n;
	while(n>1){
		n--;
		total *= n;
	}
	return total;
}


//Javascript Object Oriented Instance Method
function AI(){}
AI.prototype.factorialRecusive = function(n){
	if(n===1){
		return 1;
	}else{
		return n*this.factorialRecusive(n-1);
	}
}
AI.prototype.factorial = function(n){
	var total = n;
	while(n>1){
		n--;
		total *= n;
	}
	return total;
}


//Javascript call/invoke
var n = FactorialRecusive(5); //n=120


//Javascript call/invoke
var n = AI.factorialRecusive(5); //n=120


//Javascript call/invoke
var ai = new AI()
var n = ai.factorialRecusive(5); //n=120
//or
var n = new AI().factorialRecusive(5); //n=120


//Java Object Oriented Static Class Method
public class AI {
	public static int factorialRecusive(int n) {
		if(n==1){
			return 1;
		}else{
			return n*factorialRecusive(n-1);
		}
	}
	public static int factorial(int n){
		int total = n;
		while(n>1){
			n--;
			total *= n;
		}
		return total;
	}	
}


//Java Object Oriented Instance Method
public class AI {
	public int factorialRecusive(int n) {
		if(n==1){
			return 1;
		}else{
			return n*factorialRecusive(n-1);
		}
	}
	public int factorial(int n){
		int total = n;
		while(n>1){
			n--;
			total *= n;
		}
		return total;
	}	
}


//Java call/invoke
int n = AI.factorialRecusive(5);//n=120


//Java call/invoke
var ai = new AI()
var n = ai.factorialRecusive(5);//n=120
//or
var n = new AI().factorialRecusive(5);//n=120


//C#
public class AI
{
	public static int FactorialRecusive(int n)
	{
		if (n == 1)
		{
			return 1;
		}
		else
		{
			return n * FactorialRecusive(n - 1);
		}
	}
	public static int Factorial(int n)
	{
		int total = n;
		while (n > 1)
		{
			n--;
			total *= n;
		}
		return total;
	}
}


//C# call/invoke
int n = AI.FactorialRecusive(5);//n=120


//PHP
function FactorialRecusive($n){
	if($n==1){
		return 1;
	}else{
		return $n*FactorialRecusive($n-1);
	}
}
function Factorial($n){
	$total = $n;
	while($n>1){
		$n--;
		$total *= $n;
	}
	return $total;
}


//PHP call/invoke
$n = FactorialRecusive(5);//$n=120


//PHP
class AI {
	public static function factorialRecusive($n){
		if($n==1){
			return 1;
		}else{
			return $n*self::factorialRecusive($n-1);
		}
	}
	public static function Factorial($n){
		$total = $n;
		while($n>1){
			$n--;
			$total *= $n;
		}
		return $total;
	}
}


//PHP call/invoke
$n = AI::factorialRecusive(5);//$n=120


//PHP
class AI {
	public function factorialRecusive($n){
		if($n==1){
			return 1;
		}else{
			return $n*$this->factorialRecusive($n-1);
		}
	}
	public function factorial($n){
		$total = $n;
		while($n>1){
			$n--;
			$total *= $n;
		}
		return $total;
	}
}


//PHP call/invoke
$ai = new AI();
$n = ai->factorialRecusive(5);//$n=120


//Objective-C
@implementation AI
+(int)FactorialRecusive:(int)n{
	if(n==1){
		return 1;
	}else{
		return n*[AI FactorialRecusive:(n-1)];
	}
}
+(int)Factorial:(int)n{
	int total = n;
	while(n>1){
		n--;
		total *= n;
	}
	return total;
}
@end


//Objective-C call/invoke
int n = [AI FactorialRecusive:5];//n=120