Question

我正在编写一个使用线程来乘以两个矩阵的Java程序。我有以下代码：

public class MatrixMultiplication {
    //Declare matrices
    public static int[][] matrix1 = new int[][]{
            {1,2,3,4},{3,2,1,4}
    };
    public static int[][] matrix2 = new int[][]{
            {2,1,3,4},{4,2,5,3}
    };
    public static int[][] result = new int[4][4];
    //Threads
    public static Thread[][] threads = new Thread[4][4];

    public static void main(String[] args){
        //create worker threads with M and N hard-coded
        for(int i = 0; i < threads.length; i++) {
            for (int l = 0; l < threads[i].length; l++) {
                threads[i][l] = new Thread(new Worker(matrix1, matrix2, result, i, l));
            }
        }
        for(int i = 0; i < threads.length; i++){
            for(int l = 0; l < threads[i].length; i++){
                try {
                    threads[i][l].start();
                    threads[i][l].join();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

        System.out.println("Contents of result matrix");
        for(int i = 0; i < 4; i++)
            for(int l = 0; l < 4; l++){
                System.out.println("["+i+","+l+"] = "+result[i][l]);
            }
    }


}

class Worker implements Runnable{
    int[][] m1;
    int[][] m2;
    int[][] result;
    int row;
    int col;

    public Worker(int[][]m1, int[][] m2, int[][] result, int row, int col){
        this.m1 = m1;
        this.m2 = m2;
        this.result = result;
        this.row = row;
        this.col = col;
    }


    public void run(){result[row][col] = (m1[row][col] * m2[col][col]) + (m1[row][col+1] * m2[col+1][col]);}
}

编程在多行，值得注意的行21和Worker线程类的run方法中抛出ArrayIndexOutOfBoundsException。我尝试了几种变化无济于事，我正在寻找指导。非常感谢你。

Answer 1

有几点问题。在第21行，您使用I+1代替L+1。此外，矩阵是二维数组，只有两行，而不是四行。

Java中的多线程矩阵乘法

1 个答案: