//ChangeExpected.java
//experimnetally determine expected coin change

import java.awt.*;
import javax.swing.*;

public class ChangeExpected extends JApplet {     

    public void init() {

	String input = JOptionPane.showInputDialog( "Enter number of trials" );
	int trials = Integer.parseInt(input);
	
	int charge, quarters, dimes, nickels, pennies;
        quarters = dimes = nickels = pennies = 0;
	double eQuarters, eDimes, eNickels, ePennies;
	double eQCents, eDCents, eNCents, ePCents;
	double eTotalCents;
	
        for (int i=1; i<=trials; i++) {
	    charge = (int)(Math.random()*100);  //uniformly distributed 0..99
	    //int origCharge = charge;  //debug
	    //quarters = dimes = nickels = pennies = 0;
	    while (charge >= 25) {  //<=3 iterations
	    	quarters++;
	    	charge -= 25;
	    }
	    while (charge >= 10) {  //<=2 iterations
	    	dimes++;
	    	charge -= 10;
	    }
	    while (charge >= 5) {  //<= 1 iteration
	    	nickels++;
	    	charge -= 5;
	    }
	    pennies += charge; 
	   // JOptionPane.showMessageDialog(null,"$= "+origCharge+" Q="+
	    	//quarters+" D="+dimes+" N="+nickels+" P="+pennies);
        }
        eQuarters = (double)quarters / trials;
        eQCents = eQuarters*25;
        eDimes = (double)dimes / trials;
        eDCents = eDimes*10;
        eNickels = (double)nickels / trials;
        eNCents = eNickels*5;
        ePennies = (double)pennies / trials;
        ePCents = ePennies;
	eTotalCents = eQCents+eDCents+eNCents+ePCents;
	
        JOptionPane.showMessageDialog(null,"#Quarters= "+eQuarters+"   ¢"+eQCents+"\n"+
        	                           "#Dimes=    "+eDimes+"   ¢"+eDCents+"\n"+
        	                           "#Nickels=  "+eNickels+"   ¢"+eNCents+"\n"+
        	                           "#Pennies=  "+ePennies+"   ¢"+ePCents+"\n"+
        	                           "                 total ¢"+eTotalCents);
    }
} 
/*
 Q=1.5   .37
 D= .8   .08
 N= .4   .02
 P=2.0   .02
         .495
 
 */