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 sc = new Scanner(System.in);
        int x = sc.nextInt();
        int y = sc.nextInt();
        int z = sc.nextInt();
        //xy * yz => xz
        int[][] xy = new int[x][y];
        int[][] yz = new int[y][z];
        int[][] xz = new int[x][z];
        for(int i=0; i<x; i++){
            for(int j=0; j<y; j++){
                xy[i][j] = sc.nextInt();
            }
        }
        for(int i=0; i<y; i++){
            for(int j=0; j<z; j++){
                yz[i][j] = sc.nextInt();
            }
        }
        int[][] yzT = trans(yz, y, z);
        for(int i=0; i<x; i++){
            for(int j=0; j<z; j++){
                xz[i][j] = solution(xy[i], yzT[j]);
                System.out.print(xz[i][j] + " ");
            }
            System.out.println("");
        }
    }

    //求乘和
    private static int solution(int[] a, int[] b){
        int res = 0;
        for(int i=0; i<a.length; i++){
            res += (a[i] * b[i]);
        }
        return res;
    }

    //矩阵转置
    private static int[][] trans(int[][] rc, int r, int c){
        int[][] cr = new int[c][r];
        for(int i=0; i<c; i++){
            for(int j=0; j<r; j++){
                cr[i][j] = rc[j][i];
            }
        }
        return cr;
    }
   
}