题解 | #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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int x = in.nextInt();
            int y = in.nextInt();
            int z = in.nextInt();
            int[][] nums1 = new int[x][y];
            int[][] nums2 = new int[y][z];
            for (int i = 0; i < x; i++) {
                for (int j = 0; j < y; j++) {
                    nums1[i][j] = in.nextInt();
                }
            }
            for (int i = 0; i < y; i++) {
                for (int j = 0; j < z; j++) {
                    nums2[i][j] = in.nextInt();
                }
            }
            int[][] ans = new int[x][z];
            for (int i = 0; i < x; i++) {
                for (int j = 0; j < y; j++) {
                    for (int k = 0; k < z; k++) {
                        ans[i][k] += nums1[i][j] * nums2[j][k];
                    }
                }
            }
            for (int i = 0; i < x; i++) {
                for (int j = 0; j < z; j++) {
                    System.out.print(ans[i][j] + " ");
                }
                System.out.println();
            }
        }
    }
}