matrixtest.java

本程序实现了两个矩阵相乘的功能

import java.io.*;
class KeyInput{
   static InputStreamReader isr=new InputStreamReader(System.in);
   static BufferedReader br=new BufferedReader(isr);
   public static int readInt(){
        int i=0;
        try{
             i=Integer.parseInt(br.readLine());
        }
        catch(Exception e){
             System.out.println(e);
        }
        return i;
   }
   public static  float readFloat() {
      float f=0.0f;
      try{
           f=Float.parseFloat(br.readLine());
      }
      catch(Exception e){
           System.out.println(e);
      }
      return f;
   }
   public static  double readDouble() {
      double d=0.0;
      try{
           d=Double.parseDouble(br.readLine());
      }
      catch(Exception e){
           System.out.println(e);
      }
      return d;
   }
   public static  String readString() {
      String s="";
      try{
           s=br.readLine();
      }
      catch(Exception e){
           System.out.println(e);
      }
      return s;
   }
   public static  boolean readBoolean() {
      String s="";
      try{
           s=br.readLine();
      }
      catch(Exception e){
           System.out.println(e);
      }
      if (s.toUpperCase().equals("TRUE"))
           return true;
      else
           return false;
   }
   public static char readChar(){
      try{
           return (char)System.in.read();
      }
      catch(Exception e){
           System.out.println(e);
      }
      return ' ';
   }
}

/**************************************************************************************************************************************/
/**************************************************************************************************************************************/
/**************************************************************************************************************************************/
/**************************************************************************************************************************************/
class Matrix
{
	protected int rows;
	protected int cols;
	protected int data[][];
	protected boolean trueth;
	Matrix()
	{
		this.cols=0;
		this.rows=0;
	}
	Matrix(int rows,int cols)
	{
		this.rows=rows;
		this.cols=cols;
		this.data=new int[rows][cols];
		this.trueth=true;
	}
	Matrix(int rows,int cols,int data[][])
	{
		this.data=new int[rows][cols];
		this.rows=rows;
		this.cols=cols;
		for(int i=0;i<rows;i++)
		{
			for(int j=0;j<cols;j++)
			{
				setdata(i,j,data[i][j]);
			}
		}
		this.trueth=true;
	}
	double getdata(int rows,int cols)
	{
		return data[rows][cols];
	}
	void setdata(int rows,int cols,int value)
	{
		this.data[rows][cols]=value;
	}
	Matrix multiply(Matrix m)
	{
		Matrix p=new Matrix(this.rows,m.cols);
		if(this.cols==m.rows)
		{
			for(int i=0;i<this.rows;++i)
			{
				for(int j=0;j<m.cols;++j)
				{
					p.data[i][j]=0;
					for(int k=0;k<this.cols;++k)
					{
						p.data[i][j]+=this.data[i][k]*m.data[k][j];
					}
				}
			}
		}
		else
		{
			p.trueth=false;
		}
		return p;
	}
	void toString(Matrix q)
	{
		for(int a=0;a<q.rows;++a)
        {
        	int num=0;
        	for(int b=0;b<q.cols;++b)
        	{
        		System.out.print(q.data[a][b]);
        		num++;
        		if(num==q.cols)
        		{
        			System.out.print("\n");
        		}
        		else
        			System.out.print("\t");
        	}
        }
	}
}
class MatrixTest
{
	public static void main(String arg[])
	{
		System.out.println("请输入要创建的第一个矩阵的行列数:");
		System.out.print("行 rows=");
		int row1=KeyInput.readInt();
		System.out.print("   列 cols=");
		int col1=KeyInput.readInt();
		int s1[][]=new int[row1][col1];
        for(int i=0;i<row1;++i)
        {
        	for(int j=0;j<col1;++j)
        	{
        		s1[i][j]=(int)(Math.random()*100);
        	}
        }
        
        System.out.println("请输入要创建的第二个矩阵的行列数:");
		System.out.print("行 rows=");
		int row2=KeyInput.readInt();
		System.out.print("   列 cols=");
		int col2=KeyInput.readInt();
		int s2[][]=new int[row2][col2];
        for(int x=0;x<row2;++x)
		{
        	for(int y=0;y<col2;++y)
			{
        		s2[x][y]=(int)(Math.random()*100);
        	}
		}
        Matrix m1=new Matrix();
		m1=new Matrix(row1,col1,s1);
        Matrix m2=new Matrix();
		m2=new Matrix(row2,col2,s2);
        Matrix m3=new Matrix();
        		
        System.out.println("创建的第一个矩阵为:");  
        m1.toString(m1);
		System.out.println("创建的第二个矩阵为:");
        m2.toString(m2);
        
		m3=m1.multiply(m2);
        if(m3.trueth)
        {
			System.out.println("两个矩阵对象m1和m2的乘积为:");
            m3.toString(m3);
		}
		else 
			System.out.println("两个矩阵无法相乘！！！");
	}
}