大家好我正在尝试计算我的二维数组中包含的邻居单元格数，对角线数。之后，我将运行使用生命游戏规则的程序，将填满我的新网格。但是我被一个indexOutOfBoundsException困住了，我无法弄清楚我做错了什么，希望有人可以帮助我，这里的代码：
import java.util.Scanner;
import java.io.*;
class LifeGrid
{
private int[][] grid;
private int generation;
public LifeGrid(int x, int y, String filename) throws FileNotFoundException
{
grid = new int[x][y];
int j = 0;
Scanner scanner = new Scanner(new File(filename));
while(scanner.hasNextLine() && j < x)
{
String line = scanner.nextLine();
for(int i=0; i<line.length() && i<y; i++)
{
if(line.charAt(i) == '*')
grid[j][i] = 1;
else
grid[j][i] = 0;
}
j++;
}
scanner.close();
}
public void show()
{
for(int i=0; i<grid.length; i++)
{
for(int j=0; j<grid[i].length; j++)
{
if(grid[i][j] == 1)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
System.out.println("Generation:" + generation);
}
//Getter methods
public int getWidth() { return grid[0].length; }
public int getHeight() { return grid.length; }
public int getGeneration() { return this.generation; }
public int getCell(int x, int y) { return grid[x][y]; }
public static void main(String[] args)throws FileNotFoundException
{
LifeGrid life = new LifeGrid(6, 10, args[0]);
life.run();
}
//Check neighbours
public int neighbours(int x, int y)
{
int neighbours = 0;
if(x >= 1 && y >= 1 && x < getHeight() && y < getWidth())
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
else if(x == 0 && y == 0)
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
}
else if(x == 0 && y >= 1 && y < getWidth() && x < getHeight())
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
}
else if(x >= 1 && x < getHeight() && y == 0 && y < getWidth())
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
else if(x == getHeight() && y >= 1 && y < getWidth())
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
else if(x >=1 && x < getHeight() && y == getWidth())
{
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
}
else if(x == 0 && y == getWidth())
{
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
}
else if(x == getHeight() && y == 0)
{
if(grid[x--][y] == 1) {neighbours++;}
if(grid[x][++y] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
else if(x == getHeight() && y == getWidth())
{
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x--][y] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
}
return neighbours;
}
public void run()
{
int[][] newGrid = grid;
int[][] swapGrid = grid;;
for(int i=0; i<grid.length; i++)
{
for(int j=0; j<grid[i].length; j++)
{
if(grid[i][j] == 1)
{
if(neighbours(i,j) < 2) generation = 0;
if(neighbours(i,j) > 3) generation = 0;
if(neighbours(i,j) == 2) generation = 1;
}
if(neighbours(i,j) == 3) generation = 1;
if(generation == 1)
{
swapGrid[i][j] = 1;
newGrid = swapGrid;
}
else
{
swapGrid[i][j] = 0;
newGrid = swapGrid;
}
}
}
grid = newGrid;
show();
}
}
异常详情：
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10 at
LifeGrid.neighbours(LifeGrid.java:87) at LifeGrid.run(LifeGrid.java:150) at
LifeGrid.main(LifeGrid.java:59)
谢谢你们的直接答案，现在代码可以工作，我可以看到我的输出。但是我注意到我在run（）方法中的算法是完全错误的，因为我从生命游戏的规则中获得了不同的输出。 规则：
对于“已填充”的空间：
每个有一个或没有邻居的细胞都会死亡，好像是孤独的。 每个有四个或更多邻居的小区都会死亡，好像是人口过剩。 每个有两个或三个邻居的细胞存活下来。 对于“空”或“未填充”的空间：
每个有三个邻居的单元格都会填充。
程序使用的文件设计如下：
* * *
因此遵循我应该作为输出的规则：
*
*
*
这是我的代码：
import java.util.Scanner;
import java.io.*;
class LifeGrid
{
private int[][] grid;
private int generation;
public LifeGrid(int x, int y, String filename) throws FileNotFoundException
{
grid = new int[x][y];
int j = 0;
Scanner scanner = new Scanner(new File(filename));
while(scanner.hasNextLine() && j < x)
{
String line = scanner.nextLine();
for(int i=0; i<line.length() && i<y; i++)
{
if(line.charAt(i) == '*')
grid[j][i] = 1;
else
grid[j][i] = 0;
}
j++;
}
scanner.close();
}
public void show()
{
for(int i=0; i<grid.length; i++)
{
for(int j=0; j<grid[i].length; j++)
{
if(grid[i][j] == 1)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
System.out.println("Generation:" + generation);
}
//Getter methods
public int getWidth() { return grid[0].length; }
public int getHeight() { return grid.length; }
public int getGeneration() { return this.generation; }
public int getCell(int x, int y) { return grid[x][y]; }
public static void main(String[] args)throws FileNotFoundException
{
LifeGrid life = new LifeGrid(6, 10, args[0]);
life.run();
}
//Check neighbours
public int neighbours(int x, int y)
{
int neighbours = 0;
if(x >= 1 && y >= 1 && x < getHeight() -1 && y < getWidth() -1)
{
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y+1] == 1) {neighbours++;}
if(grid[x+1][y-1] == 1) {neighbours++;}
if(grid[x-1][y-1] == 1) {neighbours++;}
if(grid[x-1][y+1] == 1) {neighbours++;}
}
else if(x == 0 && y == 0)
{
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y+1] == 1) {neighbours++;}
}
else if(x == 0 && y >= 1 && y < getWidth() -1 && x < getHeight() -1)
{
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y+1] == 1) {neighbours++;}
if(grid[x+1][y-1] == 1) {neighbours++;}
}
else if(x >= 1 && x < getHeight() -1 && y == 0 && y < getWidth() -1)
{
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y+1] == 1) {neighbours++;}
if(grid[x-1][y+1] == 1) {neighbours++;}
}
else if(x == getHeight() && y >= 1 && y < getWidth() - 1)
{
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x-1][y-1] == 1) {neighbours++;}
if(grid[x-1][y+1] == 1) {neighbours++;}
}
else if(x >=1 && x < getHeight() - 1 && y == getWidth() )
{
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y-1] == 1) {neighbours++;}
if(grid[x-1][y-1] == 1) {neighbours++;}
}
else if(x == 0 && y == getWidth() )
{
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x+1][y] == 1) {neighbours++;}
if(grid[x+1][y-1] == 1) {neighbours++;}
}
else if(x == getHeight() && y == 0)
{
if(grid[x-1][y] == 1) {neighbours++;}
if(grid[x][y+1] == 1) {neighbours++;}
if(grid[x-1][y+1] == 1) {neighbours++;}
}
else if(x == getHeight() && y == getWidth() )
{
if(grid[x][y-1] == 1) {neighbours++;}
if(grid[x-1][y] == 1) {neighbours++;}
if(grid[x-1][y-1] == 1) {neighbours++;}
}
return neighbours;
}
public void run()
{
int[][] newGrid;
int[][] swap, old, New;
int n;
for(int i=0; i<grid.length; i++)
{
for(int j=0; j<grid[i].length; j++)
{
n = neighbours(i,j);
old = grid;
if(grid[i][j] == 1)
{
if(n < 2) {generation = 0;}
else if(n > 3) {generation = 0;}
else if(n == 2) {generation = 1; }
}
else
{
if(n == 3) {generation = 1;}
else
{generation = 0;}
}
if(generation == 1)
{
New = old;
New[i][j] = 1;
swap = New;
newGrid = swap;
grid = newGrid;
show();
grid = old;
}
else
{
New = old;
New[i][j] = 0;
swap = New;
newGrid = swap;
grid = newGrid;
show();
grid = old;
}
}
}
}
}
提前谢谢你。
答案 0 :(得分：2)
我认为这是在neighbor（）方法中。那些x ++或y ++应该是x + 1或y + 1（对于x--也是如此）。
，而不是检查大于x（或y）的1答案 1 :(得分：0)
使用示例和演练重申 dgunderson ：
//...
public int neighbours(int x, int y)
{
int neighbours = 0;
if(x >= 1 && y >= 1 && x < getHeight() && y < getWidth())
{
if(grid[x][y++] == 1) {neighbours++;}
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
//...
让：getHeight（）返回6.
设：getWidth（）返回10.
设：x等于getHeight（） - 1。
设：y等于getWidth（） - 1。
因此：
//...
public int neighbours(int x, int y)
{
int neighbours = 0;
//if 5 >= 1 && 9 >= 1 && 5 < 6 && 9 < 10...TRUE
if(x >= 1 && y >= 1 && x < getHeight() && y < getWidth())
{
//if grid[5][9] == 1) "increment y" { "increment neighbors" };
if(grid[x][y++] == 1) {neighbours++;}
//if grid[5][10] <-- WHUPS! out of bounds.
if(grid[x][y--] == 1) {neighbours++;}
if(grid[x++][y] == 1) {neighbours++;}
if(grid[x++][y++] == 1) {neighbours++;}
if(grid[x++][y--] == 1) {neighbours++;}
if(grid[x--][y--] == 1) {neighbours++;}
if(grid[x--][y++] == 1) {neighbours++;}
}
//...
此外，调用堆栈说错误特别发生在邻居中，而你在邻居中唯一做的就是操纵数组索引。