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);
        int row1=in.nextInt();
        int col1row2=in.nextInt();
        int col2=in.nextInt();
        int arr1[][]=new int[row1][col1row2];
        int arr2[][]=new int[col1row2][col2];
        for(int i=0;i<row1;i++){
            for(int j=0;j<col1row2;j++){
                arr1[i][j]=in.nextInt();
            }
        }
        for(int i=0;i<col1row2;i++){
            for(int j=0;j<col2;j++){
                arr2[i][j]=in.nextInt();
            }
        }
        int res[][]=new int[row1][col2];
        for(int i=0;i<row1;i++){
            for(int j=0;j<col2;j++){
                res[i][j]=count(i,j,arr1,arr2);
                System.out.print(res[i][j]+" ");
            }
            System.out.println();
        }
    }
    public static int count(int x,int y,int[][] a,int[][] b){
        int col1=a[0].length;
        int row2=b.length;
        int res=0;
        for(int i=0;i<col1;i++){
                // System.out.println(a[x][i]+" "+b[i][y]);
                res+=a[x][i]*b[i][y];
        }
        return res;
    }
}