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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 #include #include 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= 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; iboard, 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; icurStep == step)       {          Explore(statusHistory[i]->board, statusHistory[i]->curStep);          flag = true;       }    }    return flag; } void PrintHistory() {    for(int i=0; iboard << ' ' << 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; }
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