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# C | Factorial program

In this post, we will learn how to find the factorial of a given number. This is the most asked interview question so grasp it properly.

1. 5! = 5*4*3*2*1 = 120

2. 3! = 3*2*1 = 6

Here, 5! is pronounced as "5 factorial".

### Implementation using a loop :

```#include<stdio.h>
int main()
{
int i,fact=1,number;
printf("Enter a number: ");
scanf("%d",&number);
for(i=1;i<=number;i++){
fact=fact*i;
}
printf("Factorial of %d is: %d",number,fact);
return 0;
}   ```

Output :

```Enter a number: 5
Factorial of 5 is: 120```

### Implementation using recursion :

```#include<stdio.h>

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

void main()
{
int number;
long fact;
printf("Enter a number: ");
scanf("%d", &number);

fact = factorial(number);
printf("Factorial of %d is %ld\n", number, fact);
return 0;
}  ```

Output :

```Enter a number: 6
Factorial of 5 is: 720 ```

Happy Coding!

Please write comments if you find any bug in the above code/algorithm, or find other ways to solve the same problem.

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