Factorial of a number recursive and iterative methods in C - UCS - Unleash-Coding-Skills

## Factorial of a Number:

In mathematics, the factorial of a non negative integer n, denoted by n!, is the product  of all positive integers less than or equal to n. For example let us find factorial of 5
5! = 5*4*3*2*1=120

#### Iterative Method:

so we can simply implement a loop in iterative method.

int main()
{
int product=1,i,n;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
product=product*i;
}
printf("The factorial of a number %d is %d  ",n,product);
return 0;
}

#### Recursive Method:

int factorial(int x)
{
if(x==0||x==1)
return 1;
else
return x*factorial(x-1);
}
int main()
{
int n;
scanf("%d",&n);
printf("%d",factorial(n));
return 0;
}

Input: 5
Output :120

Recursive tree for factorial:

Happy Coding....
${\displaystyle 5!=5\times 4\times 3\times 2\times 1=120$