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Temporary code for POJ 1077




My temporary code for POJ 1077 - Eight, I want force crack it, but unfortunately it cannot work. I will find other solution for it

Description

The 15-puzzle has been around for over 100 years; even if you don't know it by that name, you've seen it. It is constructed with 15 sliding tiles, each with a number from 1 to 15 on it, and all packed into a 4 by 4 frame with one tile missing. Let's call the missing tile 'x'; the object of the puzzle is to arrange the tiles so that they are ordered as:

1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 x

where the only legal operation is to exchange 'x' with one of the tiles with which it shares an edge. As an example, the following sequence of moves solves a slightly scrambled puzzle:

1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
5 6 7 8 5 6 7 8 5 6 7 8 5 6 7 8
9 x 10 12 9 10 x 12 9 10 11 12 9 10 11 12
13 14 11 15 13 14 11 15 13 14 x 15 13 14 15 x
r-> d-> r->

The letters in the previous row indicate which neighbor of the 'x' tile is swapped with the 'x' tile at each step; legal values are 'r','l','u' and 'd', for right, left, up, and down, respectively.

Not all puzzles can be solved; in 1870, a man named Sam Loyd was famous for distributing an unsolvable version of the puzzle, and
frustrating many people. In fact, all you have to do to make a regular puzzle into an unsolvable one is to swap two tiles (not counting the missing 'x' tile, of course).

In this problem, you will write a program for solving the less well-known 8-puzzle, composed of tiles on a three by three
arrangement.

Input

You will receive a description of a configuration of the 8 puzzle. The description is just a list of the tiles in their initial positions, with the rows listed from top to bottom, and the tiles listed from left to right within a row, where the tiles are represented by numbers 1 to 8, plus 'x'. For example, this puzzle

1 2 3
x 4 6
7 5 8

is described by this list:

1 2 3 x 4 6 7 5 8
Output

You will print to standard output either the word ``unsolvable'', if the puzzle has no solution, or a string consisting entirely of the letters 'r', 'l', 'u' and 'd' that describes a series of moves that produce a solution. The string should include no spaces and start at the beginning of the line.
Sample Input

2 3 4 1 5 x 7 6 8
Sample Output

ullddrurdllurdruldr




Code:

#include "stdafx.h"
#include <iostream>
#include <stdlib.h>
#include <vector>
using namespace std;

const int SIZE = 9;
const int sizePerRow = 3;
int curHistoryIndex;
class Status
{
public:
   char* board;
   int curStep;

   Status(){}

   Status(char* b, int step){board = new char[9]; strcpy(board, b); curStep = step;}
};

int FindX(char* array)
{
   for(int i=0; i<SIZE; i++)
      if(array[i] == 'x')
         return i;
   return -1;
}

void SwapCharacter(char* array, int i, int j)
{
   char val = array[i];
   array[i] = array[j];
   array[j] = val;
}


bool GoUp(char* array)
{
   int xIndex = FindX(array);
   if(xIndex - sizePerRow >= 0)
   {
      SwapCharacter(array, xIndex, xIndex - sizePerRow);
      return true;
   }
   return false;
}

bool GoDown(char* array)
{
   int xIndex = FindX(array);
   if(xIndex + sizePerRow < SIZE)
   {
      SwapCharacter(array, xIndex, xIndex + sizePerRow);
      return true;
   }
   return false;
}
bool GoLeft(char* array)
{
   int xIndex = FindX(array);
   if(xIndex % 3 != 0)
   {
      SwapCharacter(array, xIndex, xIndex -1);
      return true;
   }
   return false;
}
bool GoRight(char* array)
{
   int xIndex = FindX(array);
   if(xIndex % 3 != 2)
   {
      SwapCharacter(array, xIndex, xIndex + 1);
      return true;
   }
   return false;
}


Status** statusHistory;

void AddToHistory(char* board, int step)
{
   for(int i=0; i<curHistoryIndex; i++)
   {
      if(0 == strcmp(statusHistory[i]->board, board)) // alreay in
      {
         return;
      }
   }

   statusHistory[curHistoryIndex++] = new Status(board, step);
}


void Explore(char* board, int curStep)
{
   char up[10];
   strcpy(up, board);
   if(true == GoUp(up))
   {
      AddToHistory(up, curStep + 1);
   }

   char down[10];
   strcpy(down, board);
   if(true == GoDown(down))
   {
      AddToHistory(down, curStep + 1);
   }

   char left[10];
   strcpy(left, board);
   if(true == GoLeft(left))
   {
      AddToHistory(left, curStep + 1);
   }

   char right[10];
   strcpy(right, board);
   if(true == GoRight(right))
   {
      AddToHistory(right, curStep + 1);
   }
}



bool RunOneStep(int step)
{
   bool flag = false;
   for(int i=0; i<curHistoryIndex; i++)
   {
      if(statusHistory[i]->curStep == step)
      {
         Explore(statusHistory[i]->board, statusHistory[i]->curStep);
         flag = true;
      }
   }
   return flag;
}

void PrintHistory()
{
   for(int i=0; i<curHistoryIndex; i++)
   {
      cout << statusHistory[i]->board << ' ' << statusHistory[i]->curStep << endl;
   }
}

int _tmain(int argc, _TCHAR* argv[])
{
   statusHistory = new Status*[999999];
   char* initArray = "12345678x";
   curHistoryIndex = 0;

   statusHistory[curHistoryIndex++] = new Status(initArray, 0);

   int step = 0;
   while(RunOneStep(step++))
   {
      if(step > 23)
         break;
   }

   PrintHistory();
   cin >> step;
    return 0;
}
[/code]



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