Question

W. A. P. find the factorial of a given no. W. A. W. R

Answer 1

The factorial of a positive number n is given by:

factorial of n (n!) = 1*2*3*4....n

The factorial of a negative number doesn't exist. And, the factorial of 0 is 1, 0! = 1

Example: Factorial of a Number

#include <stdio.h> int main( )
{ int n, i;
unsigned long long factorial = 1;
printf("Enter an integer: ");
scanf("%d",&n);
// show error if the user enters a negative integer if (n < 0)
printf("Error! Factorial of a negative number doesn't exist."); else
{
for(i=1; i<=n; ++i)
{
factorial *= i; // factorial = factorial*i;
}
printf("Factorial of %d = %llu", n, factorial); } return 0; }


Output

Enter an integer: 10 Factorial of 10 = 3628800

This program takes a positive integer from the user and computes factorial using for loop.

Since the factorial of a number may be very large, the type of factorial variable is declared as unsigned long long.

If the user enters negative number, the program displays error message.

You can also find the factorial of a number using recursion.