/*
 * Program demonstrating implementing a function 
 * that generates the factorial
 * both iteratively and recursively.
 * CISC105 06.20.05
 */
#include<stdio.h>

/*
 * Precondition: n must be positive
 * n must be small enough so that the factorial is not
 * bigger than a double or you'll get weird results.
 * (What is the maximum that n can be?)
 * Returns the value of n!
 */
double fact1( int n ) {
  double value = 1;
  int i;
  for( i=1; i <= n; i++ ) {
    value *= i;
  }
  return value;
}

/*
 * Precondition: n must be positive
 * n must be small enough so that the factorial is not
 * bigger than a double.
 * (What is the maximum that n can be?)
 * Returns the value of n!
 */
double fact2( int n ) {
  printf("Calling fact2 with parameter %d \n", n );
  if( n > 1 ) {
    return n * fact2( n-1 );
  }
  else {
    return 1;
  }
}

int main() {
  int number;

  printf("Give me a number: ");
  scanf("%d", &number);

  printf("%d! = %lf \n", number, fact1( number ) );
  printf("%d! = %lf \n", number, fact2( number ) );

  return 0;
}