Previous    Next    Applet    Source

Given three variables, i,j,k which take value 0 or 1, we want to find values for these values that cause a logical expression

        ((1-i)*j + i*(1-k) + (1-j)*k)

   import java.awt.*;
   import java.awt.event.*;
   import javax.swing.*;
   import java.applet.*;
   
   public class A extends Applet implements ActionListener {
      JTextArea out;
      JButton button;
   
      public void init () {
         setLayout(new FlowLayout());
         add(new JScrollPane(out = new JTextArea(16,30)));
         add(button = new JButton("Press Me"));
         button.addActionListener(this);
      }
   
      public void doit() {
         // Variables i,j,k will take value 0,1 only (Boolean)
         // ((1-i)*j + i*(1-k) + (1-j)*k) is then a logic expression
         // where '*' is 'and', '1-' is 'not' and '+' is 'exclusive-or'
         // What values of i,j,k make true (that is, give it value 1)?
         boolean done = false;
         for (int i=0 ; i < 2 && !done ; i++) {
            for (int j=0 ; j < 2 && !done ; j++) {
               for (int k=0 ; k < 2 && !done ; k++) {
                  if ( (((1-i)*j + i*(1-k) + (1-j)*k) % 2) == 1 ) {
                     out.append("i="+i+" j="+j+" k="+k+"\n");
                     done = true;
                  }
               }
            }
         }
         if (!done) out.append("There is no solution!\n");
      }

      public void actionPerformed (ActionEvent evt) {  doit(); }
   }