/** Copyright Henry Bottomley March 2002*/

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


public class partition extends Applet
 implements ActionListener
    {TextField box0, messagebox;
     Button calculate;
             
     public void init()
         {
         box0 = new TextField(6); 
         add (box0); 
         calculate = new Button("Calculate partitions");
         calculate.addActionListener(this);
         add (calculate);
         messagebox = new TextField(50); 
         add (messagebox);
         }    
                 
     public void actionPerformed(ActionEvent event)
        {String arg=event.getActionCommand();
                         
        if (arg=="Calculate partitions")
            {
            int n=Integer.parseInt(box0.getText().trim());
            int depent = (int) Math.sqrt(1.0d+n);
            int signArray[] = new int[2*depent+2];
            int pentArray[] = new int[2*depent+2];
            signArray[0]=-1; signArray[1]=1;
            pentArray[0]=0; pentArray[1]=1;
            for (int i=1; i<=depent; i++)
                {
                 signArray[2*i]=-signArray[2*i-2];
                 signArray[2*i+1]=-signArray[2*i-1];
                 pentArray[2*i]=(i*(3*i+1))/2;
                 pentArray[2*i+1]=((i+1)*(3*i+2))/2;
                }   
            BigInteger partitionArray[] = new BigInteger[n+1];             
            partitionArray[0]=BigInteger.valueOf(1l);
            for (int j=1; j<=n; j++)
                {BigInteger partSum=BigInteger.valueOf(0l);
                 for (int k=1; pentArray[k]<=j; k++)                  
                     {if (signArray[k]==1)
                          {partSum = partSum.add(partitionArray[j-pentArray[k]]);
                          } 
                      else
                          {partSum = partSum.subtract(partitionArray[j-pentArray[k]]);
                          }
                     } 
                 messagebox.setText(Integer.toString(j));
                 partitionArray[j] = partSum;
                }        // end of j loop 
             messagebox.setText(Integer.toString(n) + "    " + partitionArray[n].toString());
            }            // end of calculate partitions
        }                // end of actionPerormed
    }                    // end of class partition