题解 | #java矩阵乘法#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int b1 = in.nextInt();
        int b2 = in.nextInt();
        int b3 = in.nextInt();
        int [] [] a = new int[b1][b2];
        int [] [] b = new int[b2][b3];
        for (int i = 0; i < b1 ; i++) {
            for (int j = 0; j < b2 ; j++) {
                a[i][j] = in.nextInt();
            }
        }
        for (int i = 0; i < b2 ; i++) {
            for (int j = 0; j < b3 ; j++) {
                b[i][j] = in.nextInt();
            }
        }

        //相乘
        int[][] res = new int[b1][b3];
        for (int i = 0; i < b1 ; i++) {
            for (int j = 0; j < b3 ; j++) {
                for (int k = 0; k < b2 ; k++) {
                    res[i][j] += a[i][k] * b[k][j];
                }
            }
        }
        for (int i = 0; i < b1; i++) {
            for (int j = 0; j < b3; j++) {
                System.out.print(res[i][j] + " ");
            }
            System.out.println();
        }

    }
}