极客笔记Java 菜单驱动程序执行矩阵操作
Java中的数组被称为非原始数据类型，它存储了一定数量的单一类型的值。它被称为一维数组。而矩阵是指一个矩形数组或二维数组。
在本文中，我们将看到如何使用Java菜单驱动程序执行不同的矩阵操作，如加法、减法和乘法。我们将使用switch case来实现应用程序。
为了向您展示一些示例
示例1
Suppose we have inserted two different matrices of 2 rows and 3 columns. Then we will
perform matrix addition and print the result. Let the matrix be:
First Matrix:
2 3 5
9 8 7
Second Matrix:
6 4 8
9 5 4
Matrix after addition:
8 7 13
18 13 11
示例2
Suppose we have inserted two different matrices of 2 rows and 3 columns. Then we will
perform matrix subtraction and print the result. Let the matrix be:
First Matrix:
2 3 5
9 8 7
Second Matrix:
6 4 8
9 5 4
Matrix after Subtraction:
-4 -1 -3
0 3 3
示例3
Suppose we have inserted two different matrices of 2 rows and 3 columns. Then we will
perform matrix multiplication and print the result. Let the matrix be:
First Matrix:
2 3 5
9 8 7
Second Matrix:
6 4 8
9 5 4
Matrix after Multiplication:
12 12 40
81 40 28
语法
为了计算矩阵的加法、减法和乘法，我们使用了一个带有一些基本逻辑的循环。
以下是“for循环”的语法 −
for (statement 1; statement 2; statement 3) {
// code block to be executed
}
步骤
第1步 − 要求用户输入两个矩阵。
第2步 − 显示菜单。
第3步 − 要求用户输入选择。
第4步 − 使用switch case语句跳转至选择的操作。
第5步 − 打印结果。
看下面的示例程序以更清楚地理解。
示例
import java.util.*;
public class Main{
public static void main(String args[]){
Scanner s = new Scanner( System.in );
int p, q, m, n;
System.out.print("Enter number of rows in first matrix: ");
p = s.nextInt();
System.out.print("Enter number of columns in first matrix: ");
q = s.nextInt();
System.out.print("Enter number of rows in second matrix: ");
m = s.nextInt();
System.out.print("Enter number of columns in second matrix: ");
n = s.nextInt();
int a[][] = new int[p][q];
int b[][] = new int[m][n];
int c[][] = new int[m][n];
System.out.println("Enter all the elements of first matrix:");
for (int i = 0; i < p; i++) {
for (int j = 0; j < q; j++) {
a[i][j] = s.nextInt();
}
}
System.out.println("Enter all the elements of second matrix:");
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
b[i][j] = s.nextInt();
}
}
System.out.println("First Matrix:");
for (int i = 0; i < p; i++) {
for (int j = 0; j < q; j++) {
System.out.print(a[i][j]+" ");
}
System.out.println("");
}
System.out.println("Second Matrix:");
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
System.out.print(b[i][j]+" ");
}
System.out.println("");
}
mainLoop: while (true) {
System.out.println("\n***Menu***");
System.out.println("1. Matrix Addition");
System.out.println("2. Matrix Subtraction");
System.out.println("3. Matrix Multiplication");
System.out.println("4. Terminate the program");
System.out.println("Enter action number (1-4): ");
int command;
if ( s.hasNextInt() ) {
command = s.nextInt();
s.nextLine();
}
else {
System.out.println("\nILLEGAL RESPONSE. YOU MUST ENTER A NUMBER.");
s.nextLine();
continue;
}
switch(command) {
case 1:
if (p == m &&& q == n){
for (int i = 0; i < p; i++)
for (int j = 0; j <n; j++) {
for (int k = 0; k < q; k++) {
c[i][j] = a[i][j] + b[i][j];
}
}
}
System.out.println("Matrix after addition:");
for (int i = 0; i <p; i++){
for (int j = 0; j < n; j++) {
System.out.print(c[i][j]+" ");
}
System.out.println("");
}
}
else{
System.out.println("Addition would not be possible");
}
break;
case 2:
if (p == m && q == n){
for (int i = 0; i < p; i++) {
for (int j = 0; j < n; j++) {
for (int k = 0; k < q; k++) {
c[i][j] = a[i][j] - b[i][j];
}
}
}
System.out.println("Matrix after Subtraction:");
for (int i = 0; i < p; i++) {
for (int j = 0; j < n; j++) {
System.out.print(c[i][j]+" ");
}
System.out.println("");
}
}
else{
System.out.println("Subtraction would not be possible");
}
break;
case 3:
if (p == m && q == n){
for (int i = 0; i < p; i++) {
for (int j = 0; j < n; j++) {
for (int k = 0; k < q; k++) {
c[i][j] = a[i][j] * b[i][j];
}
}
}
System.out.println("Matrix after Multiplication:");
for (int i = 0; i < p; i++){
for (int j = 0; j < n; j++) {
System.out.print(c[i][j]+" ");
}
System.out.println("");
}
}
else{
System.out.println("Multiplication would not be possible");
}
break;
case 4:
System.out.println("Program terminated");
break mainLoop;
default: System.out.println("Wrong choice!!");
}
}
}
输出
Enter number of rows in first matrix: 2
Enter number of columns in first matrix: 2
Enter number of rows in second matrix: 2
Enter number of columns in second matrix: 2
Enter all the elements of first matrix:
1 2 3 4
Enter all the elements of second matrix:
5 6 7 8
First Matrix:
1 2
3 4
Second Matrix:
5 6
7 8
***Menu***
1. Matrix Addition
2. Matrix Subtraction
3. Matrix Multiplication
4. Terminate the program
Enter action number (1-4):
1
Matrix after addition:
6 8
10 12
***Menu***
1. Matrix Addition
2. Matrix Subtraction
3. Matrix Multiplication
4. Terminate the program
Enter action number (1-4):
2
Matrix after Subtraction
:
-4
-4
-4
-4
***Menu***
1. Matrix Addition
2. Matrix Subtraction
3. Matrix Multiplication
4. Terminate the program
Enter action number (1-4):
3
Matrix after Multiplication:
5 12
21 32
***Menu***
1. Matrix Addition
2. Matrix Subtraction
3. Matrix Multiplication
4. Terminate the program
Enter action number (1-4):
4
Program terminated
在这篇文章中，我们探讨了如何通过使用菜单驱动的方法，在Java中执行矩阵操作。