Question

谁会Java编程啊，要求随即产生两个矩阵，并实现两个矩阵的加法和乘法

1. 矩阵的加法和乘法（知识点：数组的声明和初始化；数组的引用和输出；循环语句的应用）数学中的矩阵运算比较常见，在java中，设计二维数组来表示矩阵。这个例子要求随即产生两个矩阵，并实现两个矩阵的加法和乘法。

Answer 1

//每一行(Row)数据用空格隔开，结束后回车 import java.io.*; import java.util.*; public class Arrtest{ public static void main(String args[]){ try{ System.out.print("set the row of the arr:\n"); BufferedReader in=new BufferedReader( new InputStreamReader(System.in)); String row=in.readLine(); System.out.print("set the line of the arr:\n"); BufferedReader in2=new BufferedReader( new InputStreamReader(System.in)); String line=in2.readLine(); int R=Integer.parseInt(row); int L=Integer.parseInt(line); Arr arr=new Arr(); System.out.print("Great the first arr:\n"); double arr1[][]=arr.greatArr(R,L); System.out.print("Great the second arr:\n"); double arr2[][]=arr.greatArr(R,L); arr.showArr(arr.addArr(arr1,arr2,R,L),R,L); }catch(Exception e){e.getMessage(); } } } class Arr { double[][] greatArr(int row,int line){ double arr[][]=new double[row][line]; for(int i=0;i<row;i++){ try{ System.out.print("input the row("+(i+1)+") numbers:\n"); BufferedReader in=new BufferedReader( new InputStreamReader(System.in)); String s=in.readLine(); StringTokenizer s_part=new StringTokenizer(s," "); for(int j=0;j<line;j++){ arr[i][j]=Double.parseDouble(s_part.nextToken()); } }catch(Exception e){e.getMessage(); } } return arr; } double[][] addArr(double[][] arr1,double[][] arr2,int row,int line){ for(int i=0;i<row;i++){ for(int j=0;j<line;j++){ arr1[i][j]=arr1[i][j]+arr2[i][j]; } } return arr1; } void showArr(double[][] arr,int row,int line){ System.out.print("the result:\r\n"); for(int i=0;i<row;i++){ for(int j=0;j<line;j++){ System.out.print(arr[i][j]+" "); } System.out.print("\r\n"); } } }