[英]JAVA Tic-Tac-Toe Minimax Algorithm keeps throwing exception
我正在尝试使用minimax算法制作井字游戏。 我正在使用本教程 。 虽然我了解此算法的工作原理,但在实现它时遇到了麻烦。 我无法使该算法通过单元测试。 它给我占用了电路板上的单元格提供了一个例外,我自己找不到解决方案。 它应该返回董事会中的获胜指数。 谢谢你的帮助。
这是失败的测试响应:
exceptions.CellIsNotAvailableException: This cell is occupied.
at board.Cell.setMarker(Cell.java:22)
at algorithm.Algorithm.minimax(Algorithm.java:204)
at algorithm.Algorithm.findBestMove(Algorithm.java:217)
at tgrevious.boardTest.BoardTest.shouldreturneight(BoardTest.java:71)
单元测试失败:
@Test
public void shouldreturneight() {
GameBoard gameBoard = new GameBoard();
Algorithm al = new Algorithm();
gameBoard.addMarkerToCell(0,Token.X);
gameBoard.addMarkerToCell(1,Token.O);
gameBoard.addMarkerToCell(2,Token.X);
gameBoard.addMarkerToCell(3,Token.O);
gameBoard.addMarkerToCell(4,Token.O);
gameBoard.addMarkerToCell(5,Token.X);
//gameBoard.addMarkerToCell(2,Token.X);
int bestMove = al.findBestMove(gameBoard.getBoard());
assertEquals(8, bestMove);
}
我抛出的异常:
public class CellIsNotAvailableException extends IllegalArgumentException {
public CellIsNotAvailableException(String message) {
super(message);
}
}
Algorithm.class
public class Algorithm {
public boolean checkRows(Cell[] board) {
if ((board[0].getMarker() == board[1].getMarker() && board[1].getMarker() == board[2].getMarker()) ||
(board[3].getMarker() == board[4].getMarker() && board[4].getMarker() == board[5].getMarker()) ||
(board[6].getMarker() == board[7].getMarker() && board[7].getMarker() == board[8].getMarker())) {
return true;
}
return false;
}
public boolean checkColumns(Cell[] board) {
if ((board[0].getMarker() == board[3].getMarker() && board[3].getMarker() == board[6].getMarker()) ||
(board[1].getMarker() == board[4].getMarker() && board[4].getMarker() == board[7].getMarker()) ||
(board[2].getMarker() == board[5].getMarker() && board[5].getMarker() == board[8].getMarker())) {
return true;
}
return false;
}
public boolean checkdiagonals(Cell[] board) {
if ((board[0].getMarker() == board[4].getMarker() && board[4].getMarker() == board[8].getMarker()) ||
(board[2].getMarker() == board[4].getMarker() && board[4].getMarker() == board[6].getMarker())) {
return true;
}
return false;
}
Token botPlayer = Token.X;
Token opponent = Token.O;
public int evaluate(Cell[] board) {
//rows across
if ((board[0].getMarker() == board[1].getMarker() && board[1].getMarker() == board[2].getMarker())) {
if (board[0].getMarker() == Token.X) {
return 10;
}
else if (board[0].getMarker() == Token.O) {
return -10;
}
}
if (board[3].getMarker() == board[4].getMarker() && board[4].getMarker() == board[5].getMarker()) {
if (board[3].getMarker() == Token.X) {
return 10;
}
else if (board[3].getMarker() == Token.O) {
return -10;
}
}
if (board[6].getMarker() == board[7].getMarker() && board[7].getMarker() == board[8].getMarker()) {
if (board[6].getMarker() == Token.X) {
return 10;
}
else if (board[6].getMarker() == Token.O) {
return -10;
}
}
//columns down
if (board[0].getMarker() == board[3].getMarker() && board[3].getMarker() == board[6].getMarker()) {
if (board[0].getMarker() == Token.X) {
return 10;
}
else if (board[0].getMarker() == Token.O) {
return -10;
}
}
if (board[1].getMarker() == board[4].getMarker() && board[4].getMarker() == board[7].getMarker()) {
if (board[1].getMarker() == Token.X) {
return 10;
}
else if (board[1].getMarker() == Token.O) {
return -10;
}
}
if (board[2].getMarker() == board[5].getMarker() && board[5].getMarker() == board[8].getMarker()) {
if (board[2].getMarker() == Token.X) {
return 10;
}
else if (board[2].getMarker() == Token.O) {
return -10;
}
}
//rows diagonally
if (board[0].getMarker() == board[4].getMarker() && board[4].getMarker() == board[8].getMarker()) {
if (board[0].getMarker() == Token.X) {
return 10;
}
else if (board[0].getMarker() == Token.O) {
return -10;
}
}
if (board[2].getMarker() == board[4].getMarker() && board[4].getMarker() == board[6].getMarker()) {
if (board[2].getMarker() == Token.X) {
return 10;
}
else if (board[2].getMarker() == Token.O) {
return -10;
}
}
return 0;
}
public boolean hasCellsLeft(Cell[] board) {
for (int i=0; i<9; i++) {
if (board[i].getMarker() == Token.EMPTY) {
return true;
}
}
return false;
}
public int minimax(Cell[] board, int depth, boolean isMax) {
int score = evaluate(board);
int best;
//if maximizer won
if (score == 10) {
return score;
}
//if minimizer won
if (score == -10) {
return score;
}
if (hasCellsLeft(board) == false) {
return 0;
}
if (isMax) {
best = -1000;
for (int i=0; i<board.length; i++) {
if (board[i].getMarker() == Token.EMPTY) {
board[i].setMarker(botPlayer);
best = Math.max(best, minimax(board, depth+1, !isMax));
board[i].setMarker(Token.EMPTY);
}
}
return best;
}
else {
best = 1000;
for (int i=0; i<board.length; i++) {
if (board[i].getMarker() == Token.EMPTY) {
board[i].setMarker(opponent);
best = Math.min(best, minimax(board, depth+1, !isMax));
board[i].setMarker(Token.EMPTY);
}
}
return best;
}
}
public int findBestMove(Cell[] board) {
int bestValue = -1000;
int bestMove = -1;
for (int i=0; i<board.length; i++) {
if (board[i].getMarker() == Token.EMPTY) {
board[i].setMarker(botPlayer);
int moveValue = minimax(board, 0, false);
board[i].setMarker(Token.EMPTY);
if (moveValue > bestValue) {
bestMove = i;
bestValue = moveValue;
}
}
}
return bestMove;
}
}
GameBoard.class
public class GameBoard {
private static final int numberOfCells = 9;
Cell[] board = new Cell[numberOfCells];
public Cell[] getBoard() {
return board;
}
public GameBoard() {
for (int i=0; i<numberOfCells; i++) {
board[i] = new Cell();
}
}
public void addMarkerToCell(int cellNumber, Token token) {
if (checkAvailableCells().contains(cellNumber)) {
board[cellNumber].setMarker(token);
}
}
public Token getMarkerAt(int cellNumber) {
return board[cellNumber].getMarker();
}
}
Cell.class
public class Cell {
Token marker;
public Cell() {
marker = Token.EMPTY;
}
public Token getMarker() {
return marker;
}
public void setMarker(Token token) {
if (marker != Token.EMPTY) {
throw new CellIsNotAvailableException("This cell is occupied.");
}
else {
marker = token;
}
}
public void resetMarker() {
marker = Token.EMPTY;
}
}
递归完成分支后,您将已评估的移动设置回Token.EMPTY
以便您可以在另一移动上执行分支。 我认为这不是逻辑错误。
best = Math.max(best, minimax(board, depth+1, !isMax));
board[i].setMarker(Token.EMPTY)
而是调用不执行检查的resetMarker
函数。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.