多线程算法实现矩阵乘法（java版）
package com.cn.cust;
import java.util.concurrent.CountDownLatch;
public class MultiThreadRecuisiveMatrixMultipy {
static int[][] a = new int[][]{{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}};
static int[][] b = new int[][]{{1, 3, 5, 7}, {2, 4, 6, 8}, {11, 13, 15, 17}, {12, 14, 16, 18}};
static int[][] c = new int[a.length][a.length];
private static int[][] recruciveMultipy(int[][] a, int[][] b, int[][] indexA, int[][] indexB, int size,CountDownLatch cdl) {
int[][] c = new int[size][size];
if (indexA[0][0] - indexA[3][0] == 0) {
c[indexA[0][0]][indexB[0][1]] = a[indexA[0][0]][indexA[0][1]] * b[indexB[0][0]][indexB[0][1]];
// System.out.println(indexA[0][0]+":"+indexB[0][1]+"="+c[indexA[0][0]][indexB[0][1]]);
} else {
int n = size;
int[][] indexA11 = new int[4][2];
indexA11[0][0] = indexA[0][0];
indexA11[0][1] = indexA[0][1];
indexA11[1][0] = indexA[1][0];
indexA11[1][1] = (indexA[1][1] + indexA[0][1]) / 2;
indexA11[2][0] = (indexA[2][0] + indexA[0][0]) / 2;
indexA11[2][1] = indexA[2][1];
indexA11[3][0] = (indexA[3][0] + indexA[0][0]) / 2;
indexA11[3][1] = (indexA[3][1] + indexA[0][1]) / 2;
int[][] indexA12 = new int[4][2];
indexA12[0][0] = indexA[0][0];
indexA12[0][1] = (indexA[1][1] + indexA[0][1]) / 2 + 1;
indexA12[1][0] = indexA[1][0];
indexA12[1][1] = indexA[1][1];
indexA12[2][0] = (indexA[3][0] + indexA[0][0]) / 2;
indexA12[2][1] = (indexA[3][1] + indexA[0][1]) / 2 + 1;
indexA12[3][0] = (indexA[3][0] + indexA[0][0]) / 2;
indexA12[3][1] = indexA[3][1];
int[][] indexA21 = new int[4][2];
indexA21[0][0] = (indexA[2][0] + indexA[0][0]) / 2 + 1;
indexA21[0][1] = indexA[0][1];
indexA21[1][0] = (indexA[3][0] + indexA[0][0]) / 2 + 1;
indexA21[1][1] = (indexA[3][1] + indexA[0][0]) / 2;
indexA21[2][0] = indexA[2][0];
indexA21[2][1] = indexA[2][1];
indexA21[3][0] = indexA[3][0];
indexA21[3][1] = (indexA[3][1] + indexA[0][0]) / 2;
int[][] indexA22 = new int[4][2];
indexA22[0][0] = (indexA[3][0] + indexA[0][0]) / 2 + 1;
indexA22[0][1] = (indexA[3][1] + indexA[0][1]) / 2 + 1;
indexA22[1][0] = (indexA[3][0] + indexA[0][0]) / 2 + 1;
indexA22[1][1] = indexA[3][1];
indexA22[2][0] = indexA[3][0];
indexA22[2][1] = (indexA[3][1] + indexA[0][1]) / 2 + 1;
indexA22[3][0] = indexA[3][0];
indexA22[3][1] = indexA[3][1];
int[][] indexB11 = new int[4][2];
indexB11[0][0] = indexB[0][0];
indexB11[0][1] = indexB[0][1];
indexB11[1][0] = indexB[1][0];
indexB11[1][1] = (indexB[1][1] + indexB[0][1]) / 2;
indexB11[2][0] = (indexB[2][0] + indexB[0][0]) / 2;
indexB11[2][1] = indexB[2][1];
indexB11[3][0] = (indexB[3][0] + indexB[0][0]) / 2;
indexB11[3][1] = (indexB[3][1] + indexB[0][1]) / 2;
int[][] indexB12 = new int[4][2];
indexB12[0][0] = indexB[0][0];
indexB12[0][1] = (indexB[1][1] + indexB[0][1]) / 2 + 1;
indexB12[1][0] = indexB[1][0];
indexB12[1][1] = indexB[1][1];
indexB12[2][0] = (indexB[3][0] + indexB[0][0]) / 2;
indexB12[2][1] = (indexB[3][1] + indexB[0][1]) / 2 + 1;
indexB12[3][0] = (indexB[3][0] + indexB[0][0]) / 2;
indexB12[3][1] = indexB[3][1];
int[][] indexB21 = new int[4][2];
indexB21[0][0] = (indexB[2][0] + indexB[0][0]) / 2 + 1;
indexB21[0][1] = indexB[0][1];
indexB21[1][0] = (indexB[3][0] + indexB[0][0]) / 2 + 1;
indexB21[1][1] = (indexB[3][1] + indexB[0][0]) / 2;
indexB21[2][0] = indexB[2][0];
indexB21[2][1] = indexB[2][1];
indexB21[3][0] = indexB[3][0];
indexB21[3][1] = (indexB[3][1] + indexB[0][0]) / 2;
int[][] indexB22 = new int[4][2];
indexB22[0][0] = (indexB[3][0] + indexB[0][0]) / 2 + 1;
indexB22[0][1] = (indexB[3][1] + indexB[0][1]) / 2 + 1;
indexB22[1][0] = (indexB[3][0] + indexB[0][0]) / 2 + 1;
indexB22[1][1] = indexB[3][1];
indexB22[2][0] = indexB[3][0];
indexB22[2][1] = (indexB[3][1] + indexB[0][1]) / 2 + 1;
indexB22[3][0] = indexB[3][0];
indexB22[3][1] = indexB[3][1];
RecruciveMultipyThread t1 = new RecruciveMultipyThread(a, b, indexA11, indexB11, size, cdl);
t1.start();
RecruciveMultipyThread t2 = new RecruciveMultipyThread(a, b, indexA12, indexB21, size, cdl);
t2.start();
RecruciveMultipyThread t3 = new RecruciveMultipyThread(a, b, indexA11, indexB12, size, cdl);
t3.start();
RecruciveMultipyThread t4 = new RecruciveMultipyThread(a, b, indexA12, indexB22, size, cdl);
t4.start();
RecruciveMultipyThread t5 = new RecruciveMultipyThread(a, b, indexA21, indexB11, size, cdl);
t5.start();
RecruciveMultipyThread t6 = new RecruciveMultipyThread(a, b, indexA22, indexB21, size, cdl);
t6.start();
RecruciveMultipyThread t7 = new RecruciveMultipyThread(a, b, indexA21, indexB12, size, cdl);
t7.start();
RecruciveMultipyThread t8 = new RecruciveMultipyThread(a, b, indexA22, indexB22, size, cdl);
t8.start();
try {
cdl.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
int[][] c11x = t1.getC();
int[][] c11y = t2.getC();
int[][] c12x = t3.getC();
int[][] c12y = t4.getC();
int[][] c21x = t5.getC();
int[][] c21y = t6.getC();
int[][] c22x = t7.getC();
int[][] c22y = t8.getC();
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
c[i][j] += c11x[i][j] + c11y[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
c[i][j] += c12x[i][j] + c12y[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
c[i][j] += c21x[i][j] + c21y[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
c[i][j] += c22x[i][j] + c22y[i][j];
}
}
}
return c;
}
next
private static class RecruciveMultipyThread extends Thread {
private int[][] a;
private int[][] b;
private int[][] indexA;
private int[][] indexB;
private int size;
private int[][] c;
private CountDownLatch cdl;
public RecruciveMultipyThread(int[][] a, int[][] b, int[][] indexA, int[][] indexB, int size,CountDownLatch cdl) {
this.a = a;
this.b = b;
this.indexA = indexA;
this.indexB = indexB;
this.size = size;
this.cdl = cdl;
}
@Override
public void run() {
CountDownLatch cdl2 = new CountDownLatch(8);
c = recruciveMultipy(a, b, indexA, indexB, size, cdl2);
cdl.countDown();
}
public int[][] getC() {
return c;
}
}
public static void printC() {
for (int i = 0; i < c.length; i++) {
for (int j = 0; j < c[i].length; j++) {
System.out.print(c[i][j] + " ");
}
System.out.println();
}
}
public static void main(String[] args) {
CountDownLatch cdl = new CountDownLatch(8);
c = recruciveMultipy(a, b,new int[][]{{0, 0}, {0, a.length - 1}, {a.length - 1, 0}, {a.length - 1, a.length - 1}},new int[][]{{0, 0}, {0, a.length - 1}, {a.length - 1, 0}, {a.length - 1, a.length - 1}},a.length, cdl);
try {
cdl.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
printC();
}
}
