更新时间:2023-09-07 09:31:34
看起来是你正在寻找一些方法来声明一个数组多少维度具有在运行时。我不知道如何可以用多维的ArrayList,或任何多维结构,你必须在编译时指定的维度来完成。
Looks like what you are looking for is for some way to declare how many dimensions an array has at runtime. I don't know how this could be done using a multidimensional ArrayList, or any multidimensional structure where you have to specify the dimensionality at compile time.
我看到的唯一的答案是使用包裹在该转换多维坐标和从底层阵列中的其位置的一类简单的线性阵列。这基本上是如何语言如C存储多维数组通过使用存储器的一个连续的块
The only answer I see is to use a simple linear array wrapped in a class that converts multidimensional coordinate to and from the its position in the underlying array. This is basically how languages such as C stores multidimensional arrays by using one contiguous chunk of memory.
在code会是这个样子:
The code would look something like this:
import java.util.*;
class MultiArray<T>{
private int[] dimensions;
private Object[] array;
public MultiArray(int ... dimensions){
this.dimensions=dimensions;
//Utils.product returns the product of the ints in an array
array=new Object[Utils.product(dimensions)];
}
public void set(T value, int ... coords){
int pos=computePos(coords);
array[pos]=value;
}
public T get(int ... coords){
int pos=computePos(coords);
return (T)(array[pos]);
}
private int computePos(int[] coords){
int pos=0;
int factor=1;
for (int i=0;i<coords.length;i++){
pos+=factor*coords[i];
factor*=dimensions[i];
}
return pos;
}
}
class Main{
public static void main(String args[]){
MultiArray<Integer> m=new MultiArray<Integer>(new int[]{5,4,3});
Random r=new Random();
for(int i=0;i<5;i++)
for(int j=0;j<4;j++)
for(int k=0;k<3;k++)
m.set(r.nextInt(),i,j,k);
for(int i=0;i<5;i++){
for(int j=0;j<4;j++){
for(int k=0;k<3;k++)
System.out.print(m.get(i,j,k)+" ");
System.out.println("");
}
System.out.println("\n");
}
}
}
class Utils{
public static int product(int...a){
int ret=1;
for (int x:a) ret*=x;
return ret;
}
}