《人生游戏》中的主类不起作用

Question

我试图为老师解决人生游戏问题。该游戏的规则是：

任何少于两个活邻居的活细胞都会死亡，就像由人口不足引起的一样。任何活细胞，有两三个活邻居的生命，传给下一代。任何具有三个以上活邻居的活细胞都会死亡，就像过度拥挤一样。任何正好有三个活邻居的死细胞都会变成活细胞，就像通过繁殖一样。

我的代码有两个问题 - 首先，我的主类似乎不起作用。其次，我通过许多如果不是其他语句来执行问题。是否有更简洁的方法来编写我的 getNeighbors（） 方法的异常？

谢谢！

import java.util.Random;
public class GameOfLife {
final static int ROWS = 6;
final static int COLUMNS = 7;
String[][] simulator;
private Random randomGenerator;
public GameOfLife() {
    simulator = new String[ROWS][COLUMNS];
    randomGenerator = new Random();
}
public void fillSpot (int row, int column) {
    simulator [row][column] = "O";
} 
private void deleteSpot (int row, int column) {
    simulator[row][column] = "";
}
// Do I need the above methods? really?
public void randomSimulation() {
    for (int i = 0; i <= ROWS; i++) {
        for (int j = 0; j <= COLUMNS; j++) {
            int random = randomGenerator.nextInt(1);
            if (random == 1) {
                fillSpot(i,j);
            }
        }
    }
}
private void getNeighbors (int row, int column) {
    int neighbors = 0;
    if (row < ROWS && row > 0 && column < COLUMNS && column > 0) {
        for (int i = row - 1; i <= row + 1; i++) {
            for (int j = column - 1; j <= column + 1; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    if (row > ROWS || column > COLUMNS || row < 0 || column < 0) {
    }
    else if (row == ROWS && column < COLUMNS && column != 0) {
        for (int i = row - 1; i <= ROWS; i++) {
            for (int j = column - 1; j <= column + 1; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    else if (row < ROWS && column == COLUMNS && row != 0) {
        for (int i = row - 1; i <= row + 1; i++) {
            for (int j = column - 1; j <= COLUMNS; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    else if (row == 0 && column < COLUMNS && column != 0) {
        for (int i = 0; i <= row + 1; i++) {
            for (int j = column - 1; j <= COLUMNS + 1; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    else if (row == 0 && column == COLUMNS) {
        for (int i = row; i <= row + 1; i++) {
            for (int j = column - 1; j <=COLUMNS; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    else if (column == 0 && row < ROWS && row != 0) {
        for (int i = row - 1; i <= row + 1; i++) {
            for (int j = column; j <= COLUMNS + 1; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    else { 
        for (int i = row; i <= row + 1; i++) {
            for (int j = column; j <= column + 1; j++) {
                String temp = simulator[i][j];
                if (temp.contains("O")) {
                    neighbors++;
                }
            }
        }
    }
    // for row == 0 && column == 0
    if (simulator [row][column].contains("O")) {
        neighbors--;
    }
    simulator[row][column] += " " + neighbors;
}
//There are wayyy too manyy clauses here for me to be comfortable. There's got to be    a way to do this cleaner
private void nextGenPlanning() {
    for (int i = 0; i <= ROWS; i++) {
        for (int j = 0; j <= COLUMNS; j++) {
            getNeighbors(i,j);
        }
    }
}
private void nextGen() {
    nextGenPlanning();
    for (int i = 0; i <= ROWS; i++) {
        for (int j = 0; j <= COLUMNS; j++) {
            String temp = simulator[i][j];
            if (temp.charAt(temp.length()) <= 1 ||  temp.charAt(temp.length()) >= 4) {
                deleteSpot(i,j);
            }
            else {
                fillSpot (i,j);
            }
        }
    }
}
public String toString() {
    String string = "";
    for (int i = 0; i < ROWS; i++) {
        string = string + "|";
        for (int j = 0; j < COLUMNS; j++) {
            String temp = simulator[i][j];
            string = string + temp.charAt(0);
        }
        string = string + "|n";
    }
    return string;
}
public String simulate (int numOfTrials) {
    String string = "";
    for (int i = 0; i <= numOfTrials; i++) {
        nextGen();
        string += toString();
    }
    return string;
}
public void main (String [] args) {
    randomSimulation();
    System.out.println(simulate(2));
}   
}

Answer 1

首先，你有：

public void main (String [] args) {
    randomSimulation();
    System.out.println(simulate(2));
}   

您应该具备：

public static void main (String[] args) {
    GameOfLife game = new GameOfLife();
    game.randomSimulation();
    System.out.println(game.simulate(2));
}   

其次，对于getNeighbors，首先要考虑"get"方法通常返回一个值。如果要计算邻居的数量，请考虑：

public int getNeighbors(int x, int y) {
  int neighbors = 0;
  int leftX = Math.max(x-1, 0); 
  int rightX = Math.min(x+1, COLUMNS); 
  int topY = Math.max(y-1, 0); 
  int bottomY = Math.min(y+1, ROWS); 
  for (int i=leftX; i < rightX; i++) {
    for (int j=topY; j < bottomY; j++) {
      if (simulator[i][j].contains('O')) { // Notice I'm using a char here, see my next comment
        neighbors++;
      }
     }
   }
   return neighbors;
}

第三，如果模拟器中的每个空格只包含一个字符值，我建议对模拟器使用 char[][] 而不是 String[][]。在 Java 中有一些关于字符串的事情你不需要被绊倒 - 例如，在 Java 中，你不能使用 == 比较字符串的值（你需要使用 String 的 equals() 方法）。

Answer 2

首先，你的主类应该是Public static void main(String[] args)的，你可以使用开关大小写，除非你真的确定是否可以使用if（blabla == blablabla &（这意味着和）blaba == babalaba）