/** Copyright Henry Bottomley May 1999*/

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.lang.Math;

public class Cdown extends Applet
 implements ActionListener
    {TextField box0, box1, box2, box3, box4, box5, targetbox, messagebox;
     int i=0; int j=0;
     int target=0;
     int[] possib = {1,1,2,2,3,3,4,4,5,5,6,7,8,9,10,25,50,75,100};
     int[] select = {0,0,0,0,0,0};
     int[] tools = {0,0,0,0,0,0};
     int[] fun = {0,0,0,0,0,0};
     int[] higher = {0,0,0,0,0,0};
     int[] lower = {0,0,0,0,0,0};
     int[] k = {0,0,0,0,0,0};
     int[] sorted={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
     String[] formula={"","","","","","","","","","","","","","","","","","","","",""};
     String[] symbol={"+", "-", "*", "/"}; 
     int bestsofar=0;
     int level=0;
     int thiscalc=0;
     int done=0;
     int domore=0;
     String newform="";
     String bestform=""; 

     public void init()
         {Button generate = new Button("Generate");
         generate.addActionListener(this);
         add (generate);
         box0 = new TextField(4); box1 = new TextField(4); box2 = new TextField(4); 
         box3 = new TextField(4); box4 = new TextField(4); box5 = new TextField(4);
         add (box0); add (box1); add (box2); add (box3); add (box4); add (box5);
         targetbox = new TextField(8);
         add (targetbox);
         Button calculate = new Button("Calculate");
         calculate.addActionListener(this);
         add (calculate);
         messagebox = new TextField(60); 
         add (messagebox);
        }    

     public void actionPerformed(ActionEvent event)
        {String arg=event.getActionCommand();
         if (arg=="Generate")
            {for (i=0; i<6;  i++) 
                {select[i] = possib[i];
                }
             for (i=6; i<19; i++) 
                 {if (Math.random()*(i+1) < 6) 
                    {select[(int)(Math.random()*6.0)] = possib[i];
                    }
                }
             box0.setText(""+select[0]); box1.setText(""+select[1]);
             box2.setText(""+select[2]); box3.setText(""+select[3]);
             box4.setText(""+select[4]); box5.setText(""+select[5]);
             targetbox.setText(""+(int)((Math.random()*900)+100));
             messagebox.setText("");

             }
         if (arg=="Calculate")
            {tools[0]=Integer.parseInt(box0.getText().trim());
             tools[1]=Integer.parseInt(box1.getText().trim());
             tools[2]=Integer.parseInt(box2.getText().trim());
             tools[3]=Integer.parseInt(box3.getText().trim());
             tools[4]=Integer.parseInt(box4.getText().trim());
             tools[5]=Integer.parseInt(box5.getText().trim());
             target=Integer.parseInt(targetbox.getText().trim());
             
             for (i=0; i<6; i++)
                {    
                 k[i]=0;
                 for (j=0; j<6; j++)
                    {if ((tools[i]) < tools[j] || (tools[i]==tools[j] && i<j)) 
                         {k[i]++;
                        }
                    }
                 sorted[k[i]]=tools[i];
                 formula[k[i]]="" + sorted[k[i]];
                }

             level=0;
             bestsofar=0;
             higher[level] = ((42 - ((6-level)*(7-level))) / 2);
             lower[level] = higher[level]+1;
             fun[level]=0;
             domore=0; 

             while (domore<2)
                 {if (5<=higher[0])
                    {domore=2;
                    }
                 else    
                    {domore=1;
    
                     if (((42 - ((6-(level+1))*(7-(level+1)))) / 2) <= lower[level])
                        {higher[level]++;
                         lower[level]=higher[level]+1;
                         fun[level]=0;
                         domore=0;
                        }
                     if ((((42 - ((6-(level+1))*(7-(level+1)))) / 2) <= (higher[level]+1)) 
                         || (4<level))
                        {if (5<=higher[0])
                            {domore=2;
                            }
                         else    
                            {level--;
                             fun[level]++;
                             domore=0;
                            }
                        }
                    }
                 if (domore==1) 
                    {//check that the function being processed means something////////////////
                     if ((fun[level]==1 && sorted[higher[level]]<=sorted[lower[level]])
                         || (fun[level]==2 && sorted[lower[level]]<=1) 
                         || (fun[level]==3 && (0<sorted[higher[level]]%sorted[lower[level]]
                                               || sorted[lower[level]]<=1) ) )
                        {fun[level]++;
                         domore=0;
                        }
                     if (4<=fun[level])
                        {lower[level]++;
                         fun[level]=0;
                         domore=0;
                        }
                    }
    
                 if (domore==1)
                    {//do the calculation///////////////////////////////////////////////////
                     newform = "(" + formula[higher[level]] + symbol[fun[level]];
                     newform = newform + formula[lower[level]] + ")";
                     if (fun[level]==0)
                        {thiscalc=sorted[higher[level]] + sorted[lower[level]];                 
                        }
                     if (fun[level]==1)
                        {thiscalc=sorted[higher[level]] - sorted[lower[level]];                 
                        }
                     if (fun[level]==2)
                        {thiscalc=sorted[higher[level]] * sorted[lower[level]];                 
                        }
                     if (fun[level]==3)
                        {thiscalc=sorted[higher[level]] / sorted[lower[level]];                 
                        }
    
                     //see if a better estimate/////////////////////////////////////////////
                     if (((target - thiscalc < target - bestsofar)  
                          && (bestsofar - target < target - thiscalc))
                         || ((target - bestsofar < target - thiscalc)
                          && (target - thiscalc < bestsofar - target)))
                        {bestsofar = thiscalc;
                         bestform = newform;
                         domore=1;
                         if (bestsofar == target)
                            {messagebox.setText("DONE IT!    " + target + " = " + bestform);
                             domore=2;
                            }
                         else
                            {messagebox.setText("Best so far: " + thiscalc + " = " + newform);
			    }
                        }
                     if (domore<2)
                        {i=((42 - ((6-(level))*(7-(level)))) / 2);
                         done=0;
                         for (j=((42 - ((6-(level+1))*(7-(level+1)))) / 2); 
                              j<((42 - ((6-(level+2))*(7-(level+2)))) / 2); j++)
                             {if (i==higher[level])
                                {i++;
                                }
                             if (i==lower[level])
                                {i++;
                                }
                             if (done==0 && (sorted[i]<=thiscalc
                                  || ((42 - ((6-(level+1))*(7-(level+1)))) / 2)<=i))
                                {sorted[j]=thiscalc;
                                 formula[j]=newform;
                                 done=1;
                                }
                             else 
                                {sorted[j]=sorted[i];
                                 formula[j]=formula[i];
                                 i++;
                                }
                            }
                         level++;
                         fun[level]=0;
                         higher[level] = ((42 - ((6-(level))*(7-(level)))) / 2);
                         lower[level] = higher[level]+1;
                         domore=0;
                        }           
                    }
                } 
             if (5<=higher[0])
                {messagebox.setText("TRIED EVERYTHING  Best: " + bestsofar + " = " + bestform);
                }
            }
        }
    }