// CS215
// change.cpp
// Graham Matthews

#include <iostream>
#include <fstream> // ifstream, ofstream
#include <cstdlib>   // exit()
#include <string>
#include <iomanip>

/* PROBLEM STATEMENT
   Write a program that will read a series of positive integers each
   representing a number of cents from a file. For each integer, the program
   will compute the maximum number of dollars, quarters, dimes, and pennies
   that would be needed to give out the amount of change. But nickels are boring
   so they don't count. The results are to be output to a file in a tabular
   format as shown below with each field having a width of 10.

   Function: compute_change
   Analysis
   Objects                Type             Movement           Name
   ------------------------------------------------------------------
   calc_number            int              received           number
   calc_dollars           int              passed back        dollars
   calc_quarters          int              passed back        quarters
   calc_dimes             int              passed back        dimes
   calc_pennies           int              passed back        pennies
*/

// No returned objects, so void function

void compute_change (int calc_number,
		     int & calc_dollars,
		     int & calc_quarters,
		     int & calc_dimes,
		     int & calc_pennies);

int main (int args, char * argv[])
{
   using namespace std;

   // DECLARE VARIABLES HERE

   int number=0, dollars, quarters, dimes, pennies;

   // 1.1 Check for correct number of arguments.

  if (args !=3)
    {
      cerr << "Usage: " << argv[0] << " inputfile outputfile" << endl;
      exit(1);
    }

  // 1.2 Open and check for successful file open.

 ifstream infile (argv[1]); // explicit-value construction of the input file
 ofstream outfile (argv[2]); // output file
 if (!infile)
   {
     cerr << "Invalid input file" << endl;
     exit(1);
   }
 else if (!outfile)
   {
     cerr << "Invalid output file/location." << endl;
     exit(1);
   }
 // Print table header
 outfile << "    Amount   Dollars  Quarters     Dimes   Pennies" << endl << endl;
 // 1.3 Read number
 while(!infile.eof())
   {
     infile>>number;
     // Compute change function call
     compute_change(number, dollars, quarters, dimes, pennies);
     // Display results
     const char separator = ' ';
     const int numWidth = 10;

     outfile << right << setw(numWidth) << setfill(separator) << number;
     outfile << right << setw(numWidth) << setfill(separator) << dollars;
     outfile << right << setw(numWidth) << setfill(separator) << quarters;
     outfile << right << setw(numWidth) << setfill(separator) << dimes;
     outfile << right << setw(numWidth) << setfill(separator) << pennies << endl;
   }

   // 4. Close files
   infile.close();
   outfile.close();

   return 0;
}  // end main

// FUNCTION DEFINITION GOES HERE
    void compute_change (int calc_number,
			 int & calc_dollars,
			 int & calc_quarters,
			 int & calc_dimes,
			 int & calc_pennies)
{
  calc_dollars = 0;
  calc_quarters = 0;
  calc_dimes = 0;
  calc_pennies = 0;
  while(calc_number>0)
    {
      if (calc_number>=100)
	{
	  calc_dollars++;
	  calc_number = calc_number-100;
	}
      else if (calc_number>=25)
	{
	  calc_quarters++;
	  calc_number = calc_number-25;
	}
      else if (calc_number>=10)
	{
	  calc_dimes++;
	  calc_number=calc_number-10;
	}
      else if (calc_number>=1)
	{
	  calc_pennies++;
	  calc_number=calc_number-1;
	}
    }
}