import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.util.Random;
 
public class Puzzle {
 private long step = 0;
 private int n = 6;// 宮格基數(shù)
 private int[][] puzzle;
 private int resetBlock = 0;//
 //空白塊位置
 private int whiteBlockX;
 private int whiteBlockY;
  
 //當(dāng)前要準(zhǔn)備移動(dòng)的塊的坐標(biāo)即復(fù)位塊
 private int resetBlockX;
 private int resetBlockY;
  
 private boolean isPrint=false;
  
 public Puzzle() {
  init();
 }
 
 public Puzzle(int n) {
  this.n = n;
  init();
 }
 
 private void init() {
  puzzle = new int[n][n];
  for (int y = 0; y < n; y++) {
   for (int x = 0; x < n; x++) {
    puzzle[y][x] = x + y * n;
   }
  }
  whiteBlockX = n-1;
  whiteBlockY = n-1;
  int times = 100;// 打亂次數(shù)，必須是偶數(shù)
  Random random = new Random();
  while (times > 0) {
   int x0 = random.nextInt(n);
   int y0 = random.nextInt(n);
   int x1 = random.nextInt(n);
   int y1 = random.nextInt(n);
   if (x0 != x1 && y0!=y1) {// 保證是偶排序
    if((x0==n-1&&y0==n-1)||(x1==n-1&&y1==n-1)){//最后一個(gè)不調(diào)換
     continue;
    }
    times--;
    int t = puzzle[x0][y0];
    puzzle[x0][y0] = puzzle[x1][y1];
    puzzle[x1][y1] = t;
   }
  }
//  int[][] p = {{22,9 ,1 ,5 ,0 ,25 },{
//    33,23,20,26,18,21},{
//    6 ,16,17,10,34,31},{
//    19,28,32,7 ,3 ,2},{
//    11,4 ,12,14,27,24},{
//    15,29,30,8 ,13,35}};
//  puzzle = p;
 }
  
 public void sort(){
  for (int y = 0; y < n; y++) {
   for (int x = 0; x < n; x++) {
    if (x == n - 1 && y == n - 1) {// 最后一個(gè)為空白,
    } else {
     reset(x, y);
    }
   }
  }
 }
 //把塊復(fù)位移動(dòng)目標(biāo)位置
 private void reset(int targetX, int targetY) {
  // 找到復(fù)位塊當(dāng)前的位置
  initResetBlock(targetX, targetY);
  /*
   * 復(fù)位順序是從左到右，從上到下
   * 移動(dòng)方式 先上移動(dòng)，再左移動(dòng)
   * 當(dāng)前復(fù)位塊，它要復(fù)位的位置可分為 四種情況
   * 1、不在最右邊一行也不是最下面兩行
   * 2、最右邊一行 x=n-1，但不是下面兩行;
   * 3、最下面兩行 y=n-2，但不是最右邊一行;
   * 4、即使最右邊的一行也是最下面兩行
   */
  if(targetX < n-1 && targetY < n-2){
   if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
    return;//退出遞歸
   }
   resetBlockToTarget(targetX, targetY);
  }else if(targetX==n-1 && targetY < n-2){//第二種情況
   if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
    return;//退出遞歸
   }
   reset2(targetX, targetY);
  }else if(targetX < n-2 && targetY == n-2){
//   isPrint=true;
   reset3(targetX);
   return;
  }else{
   initResetBlock(n-2, n-2);
   resetBlockToTarget(n-2, n-2);
   if(whiteBlockX<n-1){
    whiteBlockRight();
   }
   if(whiteBlockY<n-1){
    whiteBlockDown();
   }
   if(whiteBlockX==n-1&&whiteBlockY==n-1){
    return;
   }
  }
  reset(targetX, targetY);//遞歸
 }
 private void initResetBlock(int targetX,int targetY){
  resetBlock = targetX + targetY * n;
  for (int y = 0; y < n; y++) {
   for (int x = 0; x < n; x++) {
    if (puzzle[y][x] == resetBlock) {// x,y就是復(fù)位塊的位置
     resetBlockX = x;
     resetBlockY = y;
     break;
    }
   }
  }
 }
 private void reset3(int targetX){
//  if(targetX>=2){
//  }
  initResetBlock(targetX, n-1);
  resetBlockToTarget(targetX, n-2);
   
  initResetBlock(targetX, n-2);
  resetBlockToTarget(targetX+1, n-2);
  l:
  while (!(whiteBlockX==targetX && whiteBlockY==n-1)) {
   if(whiteBlockY<n-1){
    whiteBlockDown();
    continue l;
   }
   if(whiteBlockX>targetX){
    whiteBlockLeft();
    continue l;
   }
   break;
  }
  whiteBlockUp();
  swapWhiteBlockAndCurrentBlock();
   
  if(puzzle[n-2][targetX]!=resetBlock||puzzle[n-1][targetX]!=(resetBlock+n)){//沒有復(fù)位成功
//   isPrint=true;
   swapWhiteBlockAndCurrentBlock();
   reset3_0();
   reset3(targetX);
  }
 }
 private void reset3_0(){
  if(resetBlockX<n-1){
   whiteBlockDown();
   whiteBlockRight();
   whiteBlockRight();
   whiteBlockUp();
   swapWhiteBlockAndCurrentBlock();
   reset3_0();
   return;
  }
  return;
 }
  
  
 private void reset2_3(){
  if(whiteBlockX==resetBlockX && whiteBlockY==resetBlockY+1){
   return;//滿足條件，退出遞歸
  }
  //白塊可能在復(fù)位塊的：左方、左下、下方
  if(whiteBlockY==resetBlockY){//左方
   whiteBlockDown();
  }else if(whiteBlockX < resetBlockX){//左下
   whiteBlockRight();
  }else {
   whiteBlockUp();
  }
  reset2_3();//遞歸
 }
  
 private void reset2_2(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//2、把復(fù)位塊移到目標(biāo)位置正下方
   return;//退出遞歸
  }
   
  //復(fù)位塊可能位置，目標(biāo)位置左方、正下方、左下方
  if(resetBlockX==targetX){//正下方 上移
   resetBlockUp(targetX, targetY);
  }else{//左方或左下方；先右移再上移
   resetBlockRight(targetX, targetY);
  }
  reset2_2(targetX, targetY);//遞歸
 }
 
 private void reset2(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
   return;//退出遞歸
  }
  /* 1、如果白塊正好占了目標(biāo)位置：如果復(fù)位塊正好在下方，交換及完成復(fù)位，如果下方不是復(fù)位塊，把白塊移開目標(biāo)位置
   * 2、把復(fù)位塊移到目標(biāo)位置正下方
   * 3、把白塊移動(dòng)復(fù)位塊下方
   * 4、按照規(guī)定的步驟復(fù)位
   */
  //第一步
  if(whiteBlockX==targetX&& whiteBlockY==targetY){
   if(whiteBlockX==resetBlockX&&whiteBlockY==resetBlockY+1){//復(fù)位塊在下方
    swapWhiteBlockAndCurrentBlock();
    return;
   }else{
    whiteBlockDown();
   }
  }
  //第二步 把復(fù)位塊移到目標(biāo)位置正下方
  reset2_2(targetX, targetY+1);
  //第三步 把白塊移動(dòng)復(fù)位塊下方
  reset2_3();
  //第四步 按照規(guī)定的步驟復(fù)位
  swapWhiteBlockAndCurrentBlock();
  whiteBlockLeft();
  whiteBlockUp();
  whiteBlockRight();
  whiteBlockDown();
  whiteBlockLeft();
  whiteBlockUp();
  whiteBlockRight();
  whiteBlockDown();
  swapWhiteBlockAndCurrentBlock();
  whiteBlockLeft();
  whiteBlockUp();
  whiteBlockUp();
  whiteBlockRight();
  swapWhiteBlockAndCurrentBlock();
 }
  
 private void resetBlockToTarget(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
   return;//退出遞歸
  }
  
  if(resetBlockY==targetY){//正左
   resetBlockLeft(targetX, targetY);
  }else{//左下，下，右下
   if(resetBlockX>=targetX){//右下||下；上移
    if(resetBlockX==n-1){//復(fù)位塊在最右邊，先左移；方便上移時(shí)統(tǒng)一的采用白塊逆時(shí)針方式
     resetBlockLeft(targetX, targetY);
    }else{
     resetBlockUp(targetX, targetY);
    }
   }else{//左下；右移
    resetBlockRight(targetX, targetY);
   }
  }
  resetBlockToTarget(targetX, targetY);//遞歸
 }
  
 private void resetBlockRight(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
   return;//退出遞歸
  }
  if(resetBlockX==n-1){//復(fù)位塊在最右邊了，無法右移，直接退出
   return;
  }
//  System.out.println("resetBlockRight");
  if(whiteBlockY<resetBlockY){//上方
   if(whiteBlockY<resetBlockY-1){//上方多行
    whiteBlockDown();
   }else{//上方一行
    if(whiteBlockX<resetBlockX+1){//左上和正上
     whiteBlockRight();
    }else{//右上
     whiteBlockDown();
    }
   }
  }else if(whiteBlockY==resetBlockY){//同一行
   if(whiteBlockX<resetBlockX){//左方
    if(whiteBlockY==n-1){//到底了，只能往上
     whiteBlockUp();
    }else{
     whiteBlockDown();
    }
   }else{//右方
    if(whiteBlockX==resetBlockX+1){
     swapWhiteBlockAndCurrentBlock();
     return;//退出遞歸
    }else{
     whiteBlockLeft();
    }
   }
  }else{//下方
   if(whiteBlockX <= resetBlockX){//左下、下
    whiteBlockRight();
   }else{//右下
    whiteBlockUp();
   }
  }
  resetBlockRight(targetX, targetY);//遞歸
 }
  
 private void resetBlockLeft(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
   return;//退出遞歸
  }
  if(resetBlockX==0){//在左邊邊界 復(fù)位塊無法左移，直接退出遞歸
   return;
  }
//  System.out.println("resetBlockLeft");
  if(whiteBlockY<resetBlockY){//上方
   if(whiteBlockY<resetBlockY-1){//上方多行
    whiteBlockDown();
   }else{//上方一行
    if(whiteBlockX==resetBlockX){//上方
     if(whiteBlockX==n-1){//最右邊，白塊無法右移，只能左移
      whiteBlockLeft();
     }else{
      if(resetBlockY==n-1){//復(fù)位塊在最低端，白塊不能順時(shí)針移動(dòng)
       whiteBlockLeft();
      }else{
       whiteBlockRight();
      }
     }
    }else if(whiteBlockX>resetBlockX){//右上方
     if(resetBlockY==n-1){//復(fù)位塊在最低端，白塊不能順時(shí)針移動(dòng)
      whiteBlockLeft();
     }else{
      whiteBlockDown();
     }
    }else{//左上方
     whiteBlockDown();
    }
   }
  }else if(whiteBlockY==resetBlockY){//左方、右方
   if(whiteBlockX<resetBlockX){//左方
    if(whiteBlockX==resetBlockX-1){//左邊一格
     swapWhiteBlockAndCurrentBlock();//退出遞歸
     return;
    }else{
     whiteBlockRight();
    }
   }else{//右方
    if(whiteBlockY==n-1){//到底了，不能下移。只能上移
     whiteBlockUp();
    }else{
     whiteBlockDown();
    }
   }
  }else{//左下、下方、右下
   if(whiteBlockX<resetBlockX){//左下
    if(whiteBlockX==resetBlockX-1){
     whiteBlockUp();
    }else{
     whiteBlockRight();
    }
   }else{//下方、右下
    whiteBlockLeft();
   }
  }
  resetBlockLeft(targetX, targetY);//遞歸
 }
  
 private void resetBlockUp(int targetX, int targetY){
  if(resetBlockX==targetX&&resetBlockY==targetY){//位置正確不用移動(dòng)
   return;//退出遞歸
  }
  if(resetBlockY==0){//復(fù)位塊到頂了，無法上移
   return;
  }
//  System.out.println("resetBlockUp");
  if (whiteBlockY < resetBlockY) {//上方
   if(whiteBlockY < resetBlockY - 1){//上方多行
    whiteBlockDown();
   }else{//上方一行
    if(whiteBlockX == resetBlockX){//白塊和復(fù)位塊在同一列（豎列） 白塊和復(fù)位塊直接交換位置
     swapWhiteBlockAndCurrentBlock();//退出遞歸
     return;
    }else{
     if(whiteBlockX<resetBlockX){//白塊在復(fù)位塊的左邊；白塊右移
      whiteBlockRight(); 
     }else{//白塊在復(fù)位塊的右邊；白塊左移
      whiteBlockLeft();
     }
    }
   }
  } else if (whiteBlockY == resetBlockY) {//白塊和復(fù)位塊同一行；白塊上移
   if(whiteBlockX<resetBlockX){//正左
    if(whiteBlockX<resetBlockX-1){//正左多格
     whiteBlockRight();
    }else{//正左一格
     if(whiteBlockY==n-1){//到底了
      whiteBlockUp();
     }else {
      if(resetBlockX==n-1){//復(fù)位塊在最右邊，無法逆時(shí)針,只有順指針移動(dòng)白塊
       whiteBlockUp();
      }else{
       whiteBlockDown();
      }
     }
    }
   }else{//正右
    whiteBlockUp();
   }
  }else{//白塊在復(fù)位塊下方，白塊需要饒過復(fù)位塊上移,白塊逆時(shí)針繞到白塊上面
   //三種情況：左下，下，右下
   if(whiteBlockX<=resetBlockX){//左下，下；白塊右移
    if(resetBlockX==n-1){//復(fù)位塊在最右邊，無法逆時(shí)針,只有順指針移動(dòng)白塊
     if(whiteBlockX==resetBlockX){//正下方
      whiteBlockLeft();
     }else{//左下方
      whiteBlockUp();
     }
    }else{
     whiteBlockRight();
    }
   }else{//右下；白塊上移
    whiteBlockUp();
   }
  }
  resetBlockUp(targetX, targetY);//遞歸
 }
  
 //白塊和復(fù)位塊交換位置
 private void swapWhiteBlockAndCurrentBlock(){
  step++;
  int tempX = whiteBlockX,tempY = whiteBlockY;
  int temp = puzzle[whiteBlockY][whiteBlockX];
  puzzle[whiteBlockY][whiteBlockX] = puzzle[resetBlockY][resetBlockX];
  puzzle[resetBlockY][resetBlockX] = temp;
  whiteBlockX = resetBlockX;
  whiteBlockY = resetBlockY;
  resetBlockX = tempX;
  resetBlockY = tempY;
  println("swap");
 }
  
 private void whiteBlockDown(){
  step++;
  int temp = puzzle[whiteBlockY][whiteBlockX];
  puzzle[whiteBlockY][whiteBlockX] = puzzle[whiteBlockY+1][whiteBlockX];
  puzzle[whiteBlockY+1][whiteBlockX] = temp;
  whiteBlockY++;
  println("↓");
 }
 private void whiteBlockUp(){
  step++;
  int temp = puzzle[whiteBlockY][whiteBlockX];
  puzzle[whiteBlockY][whiteBlockX] = puzzle[whiteBlockY-1][whiteBlockX];
  puzzle[whiteBlockY-1][whiteBlockX] = temp;
  whiteBlockY--;
  println("↑");
 }
  
 private void whiteBlockLeft(){
  step++;
  int temp = puzzle[whiteBlockY][whiteBlockX];
  puzzle[whiteBlockY][whiteBlockX] = puzzle[whiteBlockY][whiteBlockX-1];
  puzzle[whiteBlockY][whiteBlockX-1] = temp;
  whiteBlockX--;
  println("←");
 }
 private void whiteBlockRight(){
  step++;
  int temp = puzzle[whiteBlockY][whiteBlockX];
  puzzle[whiteBlockY][whiteBlockX] = puzzle[whiteBlockY][whiteBlockX+1];
  puzzle[whiteBlockY][whiteBlockX+1] = temp;
  whiteBlockX++;
  println("→");
 }
  
  
 @Override
 public String toString() {
  StringBuilder sb = new StringBuilder();
  sb.append("resetBlock=("+resetBlock+","+resetBlockX+","+resetBlockY+")\n");
  if(puzzle!=null){
   int len = String.valueOf(n*2-1).length();
   for (int y = 0; y < n; y++) {
    for (int x = 0; x < n; x++) {
     if(x>0){
      sb.append(",");
     }
     sb.append(_str(String.valueOf(puzzle[y][x]), len));
    }
    sb.append("\n");
   }
   sb.append("---------------------------------------");
  }else{
   sb.append("puzzle is null");
  }
  return sb.toString();
 }
 private String _str(String str,int len){
  str=str==null?"":str;
  if(str.length()<len){
   return _str(str+" ", len);
  }
  return str;
 }
  
 private void println(String str){
  if(isPrint){
   System.out.println(str);
   System.out.println(this);
  }
 }
 
 public static void main(String[] args) throws FileNotFoundException, UnsupportedEncodingException {
//  System.setOut(new PrintStream("e:/puzzle.txt","UTF-8"));
  Puzzle p = new Puzzle();
  System.out.println(p);
  try {
   p.sort();
  } catch (Exception e) {
   e.printStackTrace();
   System.out.println("Exception:");
  }finally{
   System.out.println(p);
  }
 }
}