/*******************************************************
PROGRAM NAME - greedy  (Problem 2)

FILE NAME = greedy.cpp

PROGRAMMER NAME - Justin C. Miller

USAGE – type 'greedyam' to run me

COMPILE – type 'make' to use my makefile

DATE - Started 09-17-2003

BUGS - I think everything works fine!

DESCRIPTION - This program runs the greedy algorithm
	      using the rational class implemented 
	      with the BigInt instead of int.
*******************************************************/

// uncomment the next line to debug this program
// #DEBUG

// include files
#include <iostream>
#include <cstdlib>

// include my own files
#include "bigint.h"
#include "rational.h"

using namespace std ;

// function prototypes
rational recipcrocal(rational) ;
void greedy(rational) ;

int main(int argc, char * argv[]){
  rational user_input ;
  cout << "Please input your rational number ( [integer][space]/[space][integer] ) :" ;
  cin >> user_input ;

  cout << "\nEgyptian Fractions..." << endl ;
  cout << user_input << " = " ;
  greedy(user_input) ;
  cout << endl << endl ;

// the code below was just to test if the
// rational class still worked after I 
// changed everything over to BigInt
#ifdef DEBUG
  rational a ;
  cout << "Please input a rational number: " ;
  cin >> a ;
  cout << "You entered: " << a << endl ;

  BigInt top(27) ;
  BigInt bot(6) ;
  rational b(top,bot) ;
  cout << "B was 27 / 6 but should now be normalized: " << b << endl ;

  cout << a << " + " << b << " = " << (a + b) << endl ;
  cout << a << " - " << b << " = " << (a - b) << endl ;
  cout << a << " * " << b << " = " << (a * b) << endl ;
  cout << a << " / " << b << " = " << (a / b) << endl ;

  cout << "The ceiling of " << a << " is " << a.ceiling() << endl ;
  cout << "The ceiling of " << b << " is " << b.ceiling() << endl ;
  
  cout << "The floor of " << a << " is " << a.floor() << endl ;
  cout << "The floor of " << b << " is " << b.floor() << endl ;
#endif

  return EXIT_SUCCESS ;
}//end of main


/**************************************************************
Function reciprocal
DESCRIPTION: returns the reciprocal of a rational number
PARAMETERS:
i: rational number you want flipped
PRE:
i: is not zero
POST:
returns the reciprocal of i
***************************************************************/
rational reciprocal(rational i){
	BigInt zero(0) ;
	if(i.numerator() == zero){
		cerr << "Can't reciprocate zero!" << endl ;
		exit(EXIT_FAILURE) ;
	}//if
	return rational(i.denominator(), i.numerator()) ;
}//end of reciprocal


/**************************************************************
Function greedy
DESCRIPTION: prints out the egyptian fractions of a rational number
PARAMETERS:
user_input: c++ string
PRE:
none
POST:
none
***************************************************************/
void greedy(rational user_input){
	rational zero(0) ;
	rational dummy ;
	bool first_time = true ;

	do{
		dummy = reciprocal(user_input) ;
		dummy = dummy.ceiling() ;
		dummy = reciprocal(dummy) ;
		if(first_time) 
			first_time = false ;
		else 
			cout << " + " ;
		cout << dummy ;
		user_input -= dummy ;
	}while(user_input.compare(zero) != 0) ;
}//end of greedy