// written to support the Triangle Puzzle by 
// Dr. Roger Webster
// 4/17/96
import java.applet.*;
import java.awt.*;
import java.net.*;
import java.util.*;

public class Board extends Object {
    protected int board[]; //board[1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 ]
            //board positions are:[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14]
          // top is zero then top/down left to right..
     protected int goal_state[]; 
    public Board() {
        // init the board to all pegs except the center hole.
        board = new int[15];
        int i = 0;
        for (i=0; i <= 14; i++)
	{
            board[i]=1;
        }
        board[4]=0; // the center hole has no peg..
 
        int x = 0;
 	goal_state = new int[15];
        for (x=0; x <= 14; x++)
	{
            goal_state[x]=0;
        }
        goal_state[4]=1; // the center hole has a peg..
     }
    
    //nth element of   
    public int nth(int sub) {
	  return (board[sub]);
    } // end nth method

    // board set.
    public void  set_to_1(int sub) {
	board[sub] = 1;
    } // end 1 method

    public void set_to_0 (int sub) {
        board[sub] = 0;
    } // end 0 method

    public void print_board() {
	int i;
        for (i=0; i <= 14; i++)
        System.out.println(board[i]) ;
    } // end print board method

    public void reset_board() {
        int i = 0;
        for (i=0; i <= 14; i++)
	{
            board[i]=1;
        }
        board[4]=0; // the center hole has no peg..
    } // end reset method
    
    public int count_ones() {
    int i = 0;
    int sum = 0;
    for (i=0; i <= 14; i++)
	{
           if( board[i]==1)
                sum = sum +1;
        }
	return(sum);
    } // end count_ones method

    public int find_peg(int peg1, int hole) {
	int peg2 = 0;
       switch (peg1)
        {
       case 0: if(hole==3)  peg2 = 1;
               if(hole==5)  peg2 = 2;  
                break;
       case 1: if(hole==6)  peg2 = 3;
               if(hole==8)  peg2 = 4;
                break;
       case 2: if(hole==7)  peg2 = 4;
               if(hole==9)  peg2 = 5;
                break;
       case 3: if(hole==0)  peg2 = 1;
               if(hole==5)  peg2 = 4;
               if(hole==12)  peg2 = 7;
               if(hole==10)  peg2 = 6;
                break;
       case 4: if(hole==11)  peg2 = 7;
               if(hole==13)  peg2 = 8;
                break;
       case 5: if(hole==0)  peg2 = 2;
               if(hole==3)  peg2 = 4;
               if(hole==12)  peg2 = 8;
               if(hole==14)  peg2 = 9;
               break;
       case 6: if(hole==1)  peg2 = 3;
               if(hole==8)  peg2 = 7;
                break;
       case 7: if(hole==2)  peg2 = 4;
               if(hole==9)  peg2 = 8;
                break;
       case 8: if(hole==1)  peg2 = 4;
               if(hole==6)  peg2 = 7;
                break;
       case 9: if(hole==2)  peg2 = 5;
               if(hole==7)  peg2 = 8;
                break;
       case 10: if(hole==3)  peg2 = 6;
                if(hole==12)  peg2 = 11;
                break;
       case 11: if(hole==4)  peg2 = 7;
                if(hole==13)  peg2 = 12;
                break;
       case 12: if(hole==14)  peg2 = 13;
                if(hole==3)  peg2 = 7;
                if(hole==5)  peg2 = 8;
                if(hole==10)  peg2 = 11;
             break;
       case 13: if(hole==4)  peg2 = 8;
                if(hole==11)  peg2 = 12;
                break;
       case 14: if(hole==12)  peg2 = 13;
                if(hole==5)  peg2 = 9;
                break;
        } // end case 
	return(peg2);
    } // end find_peg method

    public int try_jumping (int peg1, int hole) {
       int peg2;
       int returnvalue = 0;
       peg2 =  find_peg (peg1, hole);
       if (peg2 != 0)
       {
	 if (  nth(hole) == 0 &&
               nth(peg1) == 1 &&
               nth(peg2) == 1 ) // valid jump
         {
                set_to_1(hole);
                set_to_0(peg1);
                set_to_0(peg2);
         	returnvalue = peg2; // valid jump
         }
	 else
	   returnvalue = 0; // invalid jump
        }
	return(returnvalue);
     } // end try jumping method

    public boolean done() {
        if ( count_ones() == 1)
           return(true);
        else
           return(false);
    } // end done method

    public int is_equal_to_goal () 
    {
	int i;
        int count = 0;
        for (i=0; i <= 14; i++)
	{
           if( board[i] == goal_state[i])
		count++;
         }

        if ( count == 15)
           return(count);
        else
           return(count);
     } // end of is_equal

 } // end class board