// A program to determine the minimum number of coins needed to make change.
// (c) 1997 duane a. bailey
import structure.*;

public class RecursivePostage
{
    static int counter;
    //+countImpl
    public static int stampCount(int amount)
    // pre: amount >= 0
    // post: return *number* of stamps needed to make change
    //       (only use 1 cent, 20 cent, and 32 cent stamps)
    {
	int minStamps;
	Assert.pre(amount >= 0,"Reasonable amount of change.");
	if (amount == 0) return 0;
	// consider use of a penny stamp
	minStamps = 1+stampCount(amount-1);
	// consider use of a 20 cent stamp
	if (amount >= 20) {
	    int possible = 1+stampCount(amount-20);
	    if (minStamps > possible) minStamps = possible;
	}
	// consider use of a 32 cent stamp
	if (amount >= 32) {
	    int possible = 1+stampCount(amount-32);
	    if (minStamps > possible) minStamps = possible;
	}
	return minStamps;
    } 
    //-countImpl

    public static void main(String args[])
    {
	counter = 0;
	System.out.println("Stamps returned to make 42 cents: "+
			   stampCount(42));
	System.out.println(counter);
    }

    //+coinsImpl
    public static coins change(int amount)
    {
	Assert.pre(amount >= 0, "Amount must be positive.");
	coins best, possible;
	if (amount == 0) best = new coins();
	else {
	    possible = change(amount-1);
	    possible.addPenny();
	    best = possible;
	    if (amount >= 5) {
		possible = change(amount-5);
		possible.addNickle();
		if (best.total() > possible.total()) best = possible;
	    }
	    if (amount >= 10) {
		possible = change(amount-10);
		possible.addDime();
		if (best.total() > possible.total()) best = possible;
	    }
	    if (amount >= 25) {
		possible = change(amount-25);
		possible.addQuarter();
		if (best.total() > possible.total()) best = possible;
	    }
	}
	return new coins(best);
    } 
    //-coinsImpl
}

class coins
{
    int pennies, nickles, dimes, quarters;
    public coins()
    {
	pennies = nickles = dimes = quarters = 0;
    }
    public coins(coins that)
    {
	this.pennies = that.pennies;
	this.nickles = that.nickles;
	this.dimes = that.dimes;
	this.quarters = that.quarters;
    }
    public void addPenny() { pennies++; }
    public void addNickle() { nickles++; }
    public void addDime() { dimes++; }
    public void addQuarter() { quarters++; }
    public int total() { return pennies+nickles+dimes+quarters; }
    public String toString() {
	return "pennies: "+pennies+", nickles: "+nickles+
	       ", dimes: "+dimes+", quarters: "+quarters;
    }
}