问题描述
我正在为我的数据结构课程编写 Java 作业。它是通过使用回溯递归找到挂钩纸牌的解决方案。我认为我有一个很好的解决方案，通过将电路板的状态保存在堆栈中，然后在我需要倒退时弹出电路板。我无法弄清楚的问题是，为什么当我开始回溯时我的棋盘从堆栈中弹出是我当前的游戏棋盘，而不是我推到我的栈上的棋盘。我觉得我以某种方式错误地实现了堆栈，但我不确定我哪里出错了。我知道他的代码还有其他问题需要我解决，但无法回溯我的电路板真的让我很受挫。如果有人能提供见解，我将不胜感激。我的两个班目前如下。
public class Board {
private char[][] board = new char[7][7];
public Board() {
for(int i = 0; i < 7; i++) {
for (int j = 0; j < 7; j++) {
if (i == 3 && j == 3) {
board[i][j] = 'O';
} else if (i == 0 && j == 0 || i == 1 && j == 0 || i == 0 && j == 1 || i == 1 && j == 1
|| i == 0 && j == 5 || i == 1 && j == 5 || i == 0 && j == 6 || i == 1 && j == 6
|| i == 5 && j == 0 || i == 5 && j == 1 || i == 6 && j == 0 || i == 6 && j == 1
|| i == 5 && j == 5 || i == 6 && j == 6 || i == 5 && j == 6 || i == 6 && j == 5) {
board[i][j] = ' ';
} else {
board[i][j] = 'X';
}
}
}
}
public void setElement(char n,int x,int y) {
board[x][y] = n;
}
public char getElement(int x,int y ) {
return board[x][y];
}
}
import java.util.Stack;
public class Puzzle {
private static int pegs;
private static int[] move = new int [3];
static Stack<Integer> xStack = new Stack();
static Stack<Integer> yStack = new Stack();
static Stack<Integer> directionStack = new Stack();
static Stack<Board> boardState = new Stack();
public static void main(String[]args) {
Board board = new Board();
print(board);
move[0] = 0;
move[1] = 0;
move[2] = 0;
findSolution(move,board);
}
public static void print(Board board) {
for(int i = 0; i < 7; i++) {
for (int j = 0; j < 7; j++) {
System.out.print(board.getElement(i,j));
}
System.out.println();
}
}
public static void findSolution(int[] move,Board board) {
if (pegs == 1 && board.getElement(3,3) == 'X') { //correct solution
System.out.println("Solution found!");
print(board);
return;
} else if (pegs == 1 && board.getElement(3,3) != 'X') { //incorrect solution
move[0] = (int) xStack.pop();
move[1] = (int) yStack.pop();
move[2] = (int) directionStack.pop();
undo(board);
boardState.pop();
pegs++;
findSolution(move,board);
}
move = findMove(move,board);
if (move[0] == 0 && move[1] == 0) { //no moves then backtrack
move[0] = (int) xStack.pop();
move[1] = (int) yStack.pop();
move[2] = (int) directionStack.pop();
boardState.pop();
undo(board);
pegs++;
findSolution(move,board);
}
xStack.push(move[0]);
yStack.push(move[1]);
directionStack.push(move[2]); // push moves onto stack
boardState.push(board); //push board onto board stack
makeMove(move,board); //change the board
move[0] = 0;
move[1] = 0;
move[2] = 0; //reset move
System.out.println();
print(board);
findSolution(move,board);
}
private static void undo(Board board) {
for(int i = 0; i < 7; i++) {
for (int j = 0; j < 7; j++) {
board.setElement(boardState.peek().getElement(i,j),i,j);
}
}
}
private static void makeMove(int[] move,Board board) {
pegs--;
if (move[2] == 0) {
board.setElement('O',move[0],move[1]);
board.setElement('O',move[0]-1,move[1]);
board.setElement('X',move[0]-2,move[1]);
}
if (move[2] == 1) {
board.setElement('O',move[1]+1);
board.setElement('X',move[1]+2);
}
if (move[2] == 2) {
board.setElement('O',move[0]+1,move[0]+2,move[1]);
}
if (move[2] == 3) {
board.setElement('O',move[1]-1);
board.setElement('X',move[1]-2);
}
}
private static int[] findMove(int[] move,Board board) {
int i,j,k;
for (i = 0; i < 7; i++) {
if (move[0] <= i) {
for (j = 0; j < 7; j++) {
if (move[1] <= j || move[0] < i) {
for (k = 0; k < 4; k++) {
if (move[2] <= k || move[1] < j) {
if (board.getElement(i,j) == 'X') {
if (k == 0 && i > 1 && board.getElement(i-1,j) == 'X' && board.getElement(i-2,j) == 'O') {
move[0] = i;
move[1] = j;
move[2] = k;
return move;
}
if (k == 1 && j < 5 && board.getElement(i,j+1) == 'X' && board.getElement(i,j+2) == 'O') {
move[0] = i;
move[1] = j;
move[2] = k;
return move;
}
if (k == 2 && i < 5 && board.getElement(i+1,j) == 'X' && board.getElement(i+2,j) == 'O') {
move[0] = i;
move[1] = j;
move[2] = k;
return move;
}
if (k == 3 && j > 1 && board.getElement(i,j-1) == 'X' && board.getElement(i,j-2) == 'O') {
move[0] = i;
move[1] = j;
move[2] = k;
return move;
}
}
}
}
}
}
}
}
move[0] = 0;
move[1] = 0;
move[2] = 0;
return move;
}
}
解决方法
暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！
如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。
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