FACTORIAL

METHOD NO-1–>

  # include <stdio.h>

 
int main()
{
  int c, n, fact = 1;
 
  printf("PleasevEnter a number to calculate factorialn");
  scanf("%d", &n);
 
  for (c = 1; c <= n; c++)
    fact = fact * c;
 
  printf("Factorial of %d = %dn", n, fact);
 
  return 0;
}

METHOD NO-2-->

#include <stdio.h>
 
long factorial(int);
 
int main()
{
  int number;
  long fact = 1;
 
  printf("Please Enter a number to calculate factorialn");
  scanf("%d", &number);
 
  printf("%d! = %ldn", number, factorial(number));
 
  return 0;
}
 
long factorial(int n)
{
  int c;
  long result = 1;
 
  for (c = 1; c <= n; c++)
    result = result * c;
 
  return result;
}


METHOD NO-3-->
#include<stdio.h>
 
long factorial(int);
 
int main()
{
  int n;
  long f;
 
  printf("Please Enter an integer to find factorialn");
  scanf("%d", &n); 
 
  if (n < 0)
    printf("Negative integers are not allowed.n");
  else
  {
    f = factorial(n);
    printf("%d! = %ldn", n, f);
  }
 
  return 0;
}
 
long factorial(int n)
{
  if (n == 0)
    return 1;
  else
    return(n * factorial(n-1));
}