## Algorithm

Basic factorial algorithm -

Defined,

``0! = 1``

``n! = n*(n-1)*(n-2)*(n-3)...``

That means = 3! = 3 * (3-1) * (3-2).

1. Take the number
2. Set `factorial` = 1
3. Loop throw the `number`
1. Inside loop, update the `factorial = factorial * incremented no`
4. Finally, get the factorial result from `factorial`

## Code Examples

### #1 Code Example with C Programming

```Code - C Programming```

``````#include <stdio.h>

int main()
{
int i, num, fact = 1;

printf("Enter Number to Calculate Factorial: \n");
scanf("%d", &num);

for (i = 1; i  < = num; i++){
fact = fact * i;
}

printf("Factorial of %d = %d\n", num, fact);

return 0;
}``````
Copy The Code &

Input

cmd
Enter Number to Calculate Factorial: 5

Output

cmd
Factorial of 5 = 120

## Demonstration

Explanation for 5!

``````fact = 1

// Start Loop from 1 to 5

fact = fact * 1 = 1  * 1 = 1     // i = 1
fact = fact * 2 = 1  * 2 = 2     // i = 2
fact = fact * 3 = 2  * 3 = 6     // i = 3
fact = fact * 4 = 6  * 4 = 24    // i = 4
fact = fact * 5 = 24 * 5 = 120   // i = 5``````