题解 | #矩阵乘法#

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int x = in.nextInt();
        int y = in.nextInt();
        int z = in.nextInt();
        int[][] a = new int[x][y];
        int[][] b = new int[y][z];
        for (int i = 0; i < x; i++) {
            for (int j = 0; j < y; j++) {
                a[i][j] = in.nextInt();
            }
        }
        for (int i = 0; i < y; i++) {
            for (int j = 0; j < z; j++) {
                b[i][j] = in.nextInt();
            }
        }
        // int[][] c = new int[x][z];
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < x; i++) {
            for (int j = 0; j < z; j++) {
                int c=0;
                for (int k = 0; k < y; k++) {
                    // c[i][j] += a[i][k] * b[k][j];
                    c += a[i][k] * b[k][j];
                }
                // sb.append(c[i][j]);
                sb.append(c);
                if (j < z - 1) {
                    sb.append(" ");
                }
            }
            sb.append("\n");
        }
        System.out.print(sb.toString());
    }
}