Java 生活游戏没有提供所需的输出？

Question

我试图在 Java 中创建康威的生命游戏，但出于某种原因，细胞没有像它们应该的那样生和死？我想知道我的比较算法是否不正确？此外，在多次要求运行 evolve 函数后，它只是一遍又一遍地打印相同的东西....

项目 4:

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;

public class Project4 {

    private static void printGame() {
        for (char[] row : GameOfLife.grid) {
            for (char c : row) {
                System.out.print(c);
            }
            System.out.println();
        }
    }

    public static void main(String[] args) throws IOException {
        Scanner input = new Scanner(System.in); // Created a scanner
        System.out.println("Enter the file name you would like to use");
        File file = new File(input.nextLine()); // Takes file name to find file
        BufferedReader br = null;
        String line;
        int i = 0;

        try {
            br = new BufferedReader(new FileReader(file));
            while ((line = br.readLine()) != null) {
                for (int col = 0; col < line.length(); col++) {
                    GameOfLife.grid[i][col] = line.charAt(col);
                }
                i++;
                if (i == 25) {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                br.close();
            }
        }

        // Prints the initial environment
        System.out.println("Initial set: ");
        printGame();

        while (true) {
            System.out.println("Do you want to see the next generation? Y/N?");
            String q = input.nextLine();
            if (q.equalsIgnoreCase("y")) {
                GameOfLife.evolve();
                printGame();
            } else {
                System.exit(0);
            }
        }
    }
}

生命游戏:

import java.util.Arrays;

public class GameOfLife {

    static final int m = 25; // number of rows
    static final int n = 75; // number of columns
    static char[][] grid = new char[m][n]; // Creates an empty (no dots or
                                            // X's)grid of rows and columns.

    static int count_neighbors(int i, int j) {
        int nn = 0; // number of neighbors of cell(i,j)

        if (i > 0 && j > 0 && grid[i - 1][j - 1] == 'X') {
            nn++;
        }
        ;
        if (i > 0 && grid[i - 1][j] == 'X') {
            nn++;
        }
        ;
        if (i > 0 && j < 72 && grid[i - 1][j + 1] == 'X') {
            nn++;
        }
        ;
        if (j > 0 && grid[i][j - 1] == 'X') {
            nn++;
        }
        ;
        if (j < 72 && grid[i][j + 1] == 'X') {
            nn++;
        }
        ;
        if (j > 0 && i < 22 && grid[i + 1][j - 1] == 'X') {
            nn++;
        }
        ;
        if (i < 22 && grid[i + 1][j] == 'X') {
            nn++;
        }
        ;
        if (i < 22 && j < 72 && grid[i + 1][j + 1] == 'X') {
            nn++;
        }

        return nn;
    }

    static void evolve() {
        for (int i = 0; i <= 25 - 1; i++) {
            for (int j = 0; j <= 75 - 1; j++) {
                int s = count_neighbors(i, j);
                if (s < 2 || s > 3) {
                    grid[i][j] = '.';
                }
                if ((s == 2 || s == 3) && grid[i][j] == 'X') {
                    grid[i][j] = 'X';
                }
                if (s == 3 && grid[i][j] == '.') {
                    grid[i][j] = 'X';
                }
            }

        }

    }

}

Answer 1

当我实现这个时，我有一个条件来检查当前单元格是否有值......不记得确切的规则，但这是我使用@janos 提到的“快照”的版本。

static void evolve() {

    char[][] temp = new char[m][n];
    for (int r = 0; r < m; r++) {
        for (int c = 0; c < n; c++) {
            int neighbors = count_neighbors(r, c);
            boolean occupied = grid[r][c] == 'X';
            if (occupied && neighbors < 2) {
                temp[r][c] = '.';
            } else if (occupied && neighbors > 3) {
                temp[r][c] = '.';
            } else if (occupied && (neighbors == 2 || neighbors == 3)) {
                temp[r][c] = 'X';
            } else if (!occupied && neighbors == 3) {
                temp[r][c] = 'X';
            } else {
                temp[r][c] = '.';
            }
        }
    }
    grid = temp.clone();
}