如何防止用户输入相同的tic tac toe坐标?
用户输入在Game类的main方法中获取。
坐标为[x, y]的单元格可以是(0-2):
0(_)， 1 (X)或2 (O)
带有alpha - beta搜索树修剪算法的网格类
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
class Grid {
List<Cell> availableCells;
int[][] board = new int[3][3];
Scanner scan = new Scanner(System.in);
// Set limit to search tree depth
int treeDepth = 9;
List<CellsAndScores> rootsChildrenScore = new ArrayList<>();
public int score() {
int score = 0;
// Check all columns
for (int j = 0; j < 3; ++j) {
int X = 0;
int O = 0;
for (int i = 0; i < 3; ++i) {
if (board[i][j] == 0) {
} else if (board[i][j] == 1) {
X++;
} else {
O++;
}
}
score += changeInScore(X, O);
}
// Check all rows
for (int i = 0; i < 3; ++i) {
int X = 0;
int O = 0;
for (int j = 0; j < 3; ++j) {
if (board[i][j] == 0) {
} else if (board[i][j] == 1) {
X++;
} else {
O++;
}
}
score += changeInScore(X, O);
}
int X = 0;
int O = 0;
// Check diagonal (first)
for (int i = 0, j = 0; i < 3; ++i, ++j) {
if (board[i][j] == 1) {
X++;
} else if (board[i][j] == 2) {
O++;
} else {
}
}
score += changeInScore(X, O);
X = 0;
O = 0;
// Check Diagonal (Second)
for (int i = 2, j = 0; i > -1; --i, ++j) {
if (board[i][j] == 1) {
X++;
} else if (board[i][j] == 2) {
O++;
} else {
}
}
score += changeInScore(X, O);
return score;
}
private int changeInScore(int X, int O) {
int change;
if (X == 3) {
change = 100;
} else if (X == 2 && O == 0) {
change = 10;
} else if (X == 1 && O == 0) {
change = 1;
} else if (O == 3) {
change = -100;
} else if (O == 2 && X == 0) {
change = -10;
} else if (O == 1 && X == 0) {
change = -1;
} else {
change = 0;
}
return change;
}
public int alphaBetaMinimax(int alpha, int beta, int depth, int turn) {
if (beta <= alpha) {
System.out.println("Pruning at tree depth = " + depth + " alpha: " + alpha + " beta: " + beta);
if (turn == 1)
return Integer.MAX_VALUE;
else
return Integer.MIN_VALUE;
}
if (depth == treeDepth || gameOver()) {
return score();
}
List<Cell> cellsAvailable = getAvailableStates();
if (cellsAvailable.isEmpty()) {
return 0;
}
if (depth == 0) {
rootsChildrenScore.clear();
}
int maxValue = Integer.MIN_VALUE, minValue = Integer.MAX_VALUE;
for (int i = 0; i < cellsAvailable.size(); ++i) {
Cell cell = cellsAvailable.get(i);
int currentScore = 0;
if (turn == 1) {
placeAMove(cell, 1);
currentScore = alphaBetaMinimax(alpha, beta, depth + 1, 2);
maxValue = Math.max(maxValue, currentScore);
// Set alpha
alpha = Math.max(currentScore, alpha);
if (depth == 0) {
rootsChildrenScore.add(new CellsAndScores(currentScore, cell));
}
} else if (turn == 2) {
placeAMove(cell, 2);
currentScore = alphaBetaMinimax(alpha, beta, depth + 1, 1);
minValue = Math.min(minValue, currentScore);
// Set beta
beta = Math.min(currentScore, beta);
}
// reset board
board[cell.x][cell.y] = 0;
// Do not evaluate the rest of the branches after search tree is pruned
if (currentScore == Integer.MAX_VALUE || currentScore == Integer.MIN_VALUE)
break;
}
return turn == 1 ? maxValue : minValue;
}
public boolean gameOver() {
// Game is over is someone has won, or board is full (draw)
return (hasXWon() || hasOWon() || getAvailableStates().isEmpty());
}
public boolean hasXWon() {
if ((board[0][0] == board[1][1] && board[0][0] == board[2][2] && board[0][0] == 1)
|| (board[0][2] == board[1][1] && board[0][2] == board[2][0] && board[0][2] == 1)) {
// System.out.println("X Diagonal Win");
return true;
}
for (int i = 0; i < 3; ++i) {
if (((board[i][0] == board[i][1] && board[i][0] == board[i][2] && board[i][0] == 1)
|| (board[0][i] == board[1][i] && board[0][i] == board[2][i] && board[0][i] == 1))) {
// System.out.println("X Row or Column win");
return true;
}
}
return false;
}
public boolean hasOWon() {
if ((board[0][0] == board[1][1] && board[0][0] == board[2][2] && board[0][0] == 2)
|| (board[0][2] == board[1][1] && board[0][2] == board[2][0] && board[0][2] == 2)) {
// System.out.println("O Diagonal Win");
return true;
}
for (int i = 0; i < 3; ++i) {
if ((board[i][0] == board[i][1] && board[i][0] == board[i][2] && board[i][0] == 2)
|| (board[0][i] == board[1][i] && board[0][i] == board[2][i] && board[0][i] == 2)) {
// System.out.println("O Row or Column win");
return true;
}
}
return false;
}
public List<Cell> getAvailableStates() {
availableCells = new ArrayList<>();
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
if (board[i][j] == 0) {
availableCells.add(new Cell(i, j));
}
}
}
return availableCells;
}
public void placeAMove(Cell Cell, int player) {
board[Cell.x][Cell.y] = player; // player = 1 for X, 2 for O
}
public Cell returnBestMove() {
int MAX = -100000;
int best = -1;
for (int i = 0; i < rootsChildrenScore.size(); ++i) {
if (MAX < rootsChildrenScore.get(i).score) {
MAX = rootsChildrenScore.get(i).score;
best = i;
}
}
return rootsChildrenScore.get(best).cell;
}
public void displayBoard() {
System.out.println();
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
if (board[i][j] == 0)
System.out.print("_" + " ");
if (board[i][j] == 1)
System.out.print("X" + " ");
if (board[i][j] == 2)
System.out.print("O" + " ");
}
System.out.println("");
}
System.out.println();
}
public void resetGrid() {
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
board[i][j] = 0;
}
}
}
}
细胞类
class Cell {
int x, y;
public Cell(int x, int y) {
this.x = x;
this.y = y;
}
public String toString() {
return "[" + x + ", " + y + "]";
}
}
class CellsAndScores {
int score;
Cell cell;
CellsAndScores(int score, Cell cell) {
this.score = score;
this.cell = cell;
}
}
带有main方法的游戏类-接受用户输入
import java.util.Random;
public class Game {
public static void main(String[] args) {
Grid grid = new Grid();
Random random = new Random();
grid.displayBoard();
System.out.print("Who moves first? [1]Computer(X) [2]User(O): ");
int turn = grid.scan.nextInt();
if (turn == 1) {
Cell p = new Cell(random.nextInt(3), random.nextInt(3));
grid.placeAMove(p, 1);
grid.displayBoard();
}
while (!grid.gameOver()) {
int x = 0, y = 0;
System.out.print("Please enter an x coordinate [0-2]: ");
x = grid.scan.nextInt();
System.out.print("Please enter an y coordinate [0-2]: ");
y = grid.scan.nextInt();
Cell userMove = new Cell(y, x);
grid.placeAMove(userMove, 2); // 2 for O and O is the user
grid.displayBoard();
if (grid.gameOver())
break;
grid.alphaBetaMinimax(Integer.MIN_VALUE, Integer.MAX_VALUE, 0, 1);
for (CellsAndScores pas : grid.rootsChildrenScore)
System.out.println("Cell: " + pas.cell + " Score: " + pas.score);
grid.placeAMove(grid.returnBestMove(), 1);
grid.displayBoard();
}
if (grid.hasXWon()) {
System.out.println("Unfortunately, you lost!");
grid.resetGrid();
} else if (grid.hasOWon()) {
System.out.println("You win!");
grid.resetGrid();
} else {
System.out.println("It's a draw!");
grid.resetGrid();
}
}
}
我的答案是在Grid.java类中添加一个布尔检查方法，然后在主方法中调用这个布尔检查方法，然后在placemove()方法之前调用这个布尔检查方法。
例如，在Grid.java类中，添加以下方法:/*
* Return true if space is ok to use.
*/
public boolean isMoveOK(Cell cell) {
return board[cell.x][cell.y] == 0;
}
这样，使用您已经存在的0/1/2值来跟踪空/X/O空间值，您可以提供检查，看看空间值是否为零。
这将是在你的主方法中使用它的一种方式，来回答你的问题，"我如何防止用户输入相同的井字坐标?"'
Cell userMove = new Cell(y, x);
if (grid.isMoveOK(userMove)) {
grid.placeAMove(userMove, 2); // 2 for O and O is the user
} else {
System.out.println("Please try a different space/cell");
continue;
}
grid.displayBoard();
if (grid.gameOver())
break;
希望这能回答你的问题!:)
欢呼