Java实验作业2

实验2 面向对象程序设计（6学时）

二、实验内容
1.设计一个教师类Teacher（属于cn.net.sdkd包），要求：
1)属性有编号（int no）、姓名（String name）、年龄（int age）、所属学院（String seminary），为这些属性设置相应的get和set方法。
2)为Teacher类重写equals方法，要求：当两个教师对象的no相同时返回true。
3)重写Teacher类的toString方法，通过该方法可以返回“编号为、姓名为、年龄为的学院老师”形式的字符串。
4)由多个Teacher对象所形成的数组可以以两种方法排序（编号由低到高排序）：1）使用Arrays.sort(Object[] a)方法；2）使用Arrays.sort(Object[] a, Comparator c)方法。
5)再定义一个类TeacherManagement（属于cn.sd包），提供方法search，方法可以在一组给定的教师中，根据姓名（或年龄）返回等于指定姓名（或年龄）的教师的字符串信息，信息格式为：“编号为**、姓名为**、年龄为的学院老师”。如果没有满足条件的教师，则返回“没有符合条件的教师”。
6)构造main方法进行测试。**

package cn.sd;

import cn.net.sdkd.Teacher;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

public class TeacherManagement {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<Teacher> teachers = new ArrayList<>();
        while(true)
        {
            System.out.println("是否输入? Y/y");
            String flag = sc.next();
            if(flag.equals("Y")||flag.equals("y"))
            {
                int no = sc.nextInt();
                String name = sc.next();
                int age = sc.nextInt();
                String seminary = sc.next();
                Teacher t1 = new Teacher(no,name,age,seminary);
                teachers.add(t1);
            }
            else
            {
                break;
            }

        }
        System.out.println("输入要查找的老师");
        int no = sc.nextInt();
        String name = sc.next();
        int age = sc.nextInt();
        String seminary = sc.next();
        Teacher t2 = new Teacher(no,name,age,seminary);
        search(teachers,t2);
    }
    public static void search(ArrayList<Teacher> t2,Teacher t1)
    {
        boolean flag = false;
        Iterator<Teacher> it = t2.iterator();
        while(it.hasNext())
        {
            if(it.next().name.equals(t1.name))
                flag = true;
        }
        if(!flag)
            System.out.println("没有符合条件的老师");
        else
            System.out.println(t1.toString());
    }
}

package cn.net.sdkd;

import javax.swing.*;
import java.util.Comparator;

public class Teacher implements Comparable<Teacher>, Comparator<Teacher> {
    public int no;
    public String name;
    public int age;
    public String seminary;

    @Override
    public int compare(Teacher teacher, Teacher t1) {
        if(teacher.no<t1.no)
            return 1;
        else if(teacher.no==t1.no)
            return 0;
        else
            return -1;
    }

    @Override
    public boolean equals(Object obj) {
        Teacher teacher = (Teacher) obj;
        if(this.no==teacher.no)
            return true;
        else
            return false;
    }

    @Override
    public String toString() {
        return "编号为"+this.no+",姓名为"+this.name+",年龄为"+this.age+"的"+this.seminary+"学院老师";
    }

    public Teacher(int no, String name, int age, String seminary) {
        this.no = no;
        this.name = name;
        this.age = age;
        this.seminary = seminary;
    }
    @Override
    public int compareTo(Teacher teacher) {
        if(this.no<teacher.no)
            return 1;
        else if(this.no == teacher.no)
            return 0;
        else
            return -1;
    }


    public Teacher() {
    }

    public int getNo() {
        return no;
    }

    public void setNo(int no) {
        this.no = no;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSeminary() {
        return seminary;
    }

    public void setSeminary(String seminary) {
        this.seminary = seminary;
    }



}

2.设计一个带表头的双向链表（链表中数据的具体类型可以随意），提供以下方法：（1）insert：在某个位置插入对象；（2）insert：在链表的最后插入对象；（2）delete：在某个位置删除对象；（3）delete：删除链表中与x相同的元素；（4）size：返回当前链表中对象的个数；（5）isEmpty：判断链表是否为空；（6）traverse：遍历链表，打印出所有的元素；（7）getData：取得某个位置的对象。构造main函数进行测试。

package Test;

import java.util.LinkedList;
import java.util.Scanner;


public class Main {
    class Node {
        int data;
        Node next;
        Node front;
        //next:后继   front:前驱
        public Node() {
            data = 0;
            next = null;
            front = null;
        }

        public Node(int e, Node pre, Node next) {
            this.data = e;
            this.front = pre;
            this.next = next;
        }

        public void setData(int a) {
            this.data = a;
        }

        public Object getData() {
            return this;
        }

    }

    public int size;
    public Node head;
    public Node rear;

    public Main() {
        this.size = 0;
        head = new Node();
        rear = new Node(0, head, null);
        head.next = rear;

    }

    //尾插法
    public void insert(int e) {
        Node t = new Node(e, null, null);
        rear.front.next = t;
        t.front = rear.front;
        t.next = rear;
        rear.front = t;
        size++;
    }

    public void insert(int x, int e) {
        Node t = new Node(e, null, null);
        Node f = head;
        for (int i = 0; i < x; i++) {
            f = f.next;
        }
        t.next = f;
        t.front = f.front;
        f.front.next = t;
        f.front = t;
        size++;
    }

    public void delete(int x) {
        Node f = head.next;
        while (f.next != null) {
            if (f.data == x) {
                f.front.next = f.next;
                f.next.front = f.front;
            }
            f = f.next;
        }
    }

    public void delete(int pos, Main t) {
        Node f = head;
        for (int i = 0; i < pos; i++) {
            f = f.next;
        }
        f.front.next = f.next;
        f.next.front = f.front;
    }

    public boolean isEmpty() {
        if (size == 0)
            return true;
        else
            return false;
    }

    public int size() {
        return size;
    }

    public void traverse() {
        Node f = head.next;
        while (f.next != null) {
            System.out.print(f.data+" ");
            f = f.next;
        }
    }

    public static void main(String[] args) {
        Main str = new Main();
        str.insert(1);
        str.insert(2);
        str.insert(3);
        str.insert(2,4);
        str.insert(5);
        str.insert(6);
        System.out.println("size = " + str.size);

        str.traverse();
        System.out.println();

        str.delete(2);

        str.traverse();
        System.out.println();

        str.delete(3, str);
        str.traverse();
    }

}

3.使用一维数组编码实现一个栈（Stack）类，要求提供以下操作：（1）boolean isEmpty()：判断栈当前是否为空；（2）入栈操作void push(obj)：把数据元素obj插入堆栈；（3）出栈操作Object pop()：出栈，并返回删除的数据元素；（4）Object getTop()：取堆栈当前栈顶的数据元素并返回；（5）利用Stack类实现一个方法：输入一个正整数，输出该整数所对应的二进制数。

class stack{
    private Object[] stack;
    private int need;
    stack(int n)
    {
        stack = new Object[n];
        for(int i = 0;i < n;i++)
        {
            stack[i] = null;
        }
        need = n;
    }

    public boolean isEmpty()
    {
        if(need == stack.length)
            return true;
        else
            return false;
    }

    void push(Object obj)
    {
        if(need == 0)
        {
            System.out.println("空间已满!");
            return;
        }
        else
        {
            stack[need-1] = obj;
            need--;
        }
    }
    Object pop()
    {
        Object object = stack[need];
        need++;
        stack[need] = null;
        return object;
    }

    Object getTop()
    {
       return stack[need];
    }

    int GetTwo()
    {
        return Integer.parseInt((String) stack[need],2);
    }
}

4.利用二维数组（double[]）实现一个矩阵类：Matrix。要求提供以下方法：（1）set（int row, int col, double value）：将第row行第col列的元素赋值为value；（2）get（int row，int col）：取第row行第col列的元素；（3）width()：返回矩阵的列数；（4）height()：返回矩阵的行数；（5）Matrix add（Matrix b）：返回当前矩阵与矩阵b相加后的矩阵；（6）Matrix multiply（Matrix b）：返回当前矩阵与矩阵b相乘后的矩阵。（7）Matrix transpose()：返回当前矩阵的转置矩阵；（8）getMax()：返回矩阵中的最大值及其所在行和列；（9）print()：以行和列的形式打印出当前矩阵。**

import java.text.DecimalFormat;

import java.util.*;

class Matrix{
    private int row;//行
    private int col;//列
    //private double value;
    double [][]Data;
    public Matrix(int row, int col,double [][]Data) {
        this.row = row;
        this.col = col;
        //    this.value = value;
        this.Data = Data;
    }

    public void setMatrix(int row , int col, double value) {
        this.Data[row - 1][col - 1] = value;
    }

    public double getMatrix(int row, int col) {
        return Data[row - 1][col - 1] ;
    }

    public int width() {
        return row;
    }

    public int height() {
        return col;
    }

    public Matrix add(Matrix b) {
        if(this.width() != b.width() && this.height() != b.height()) {
            return null;
        }

        double add[][] = new double[this.row][this.col];

        for(int i = 0;i<col;i++) {
            for(int j = 0;j<row;j++) {
                add[i][j] = this.Data[i][j] + b.Data[i][j];
            }
        }

        Matrix another = new Matrix(this.col,this.row,add);
        System.out.println("after add:");
        return another;
    }

    public Matrix multiply(Matrix b) {
        if(this.col != b.row) {
            return null;
        }

        double mul[][] = new double[this.row][b.col];
        double temp = 0;
        for(int i = 0;i<this.row;i++) {
            for(int k = 0;k<b.col;k++) {
                for(int j = 0;j<this.col;j++)
                {
                    temp += this.Data[i][j] * b.Data[j][k];
                }
                mul[i][k] = temp;
                temp = 0;
            }
        }

        Matrix another = new Matrix(this.row, b.col, mul);
        System.out.println("after multiply:");
        return another;

    }

    public Matrix transpose() {
        double tran[][] = new double[this.row][this.col];
        for(int i = 0;i<this.row;i++) {
            for(int j = 0;j<this.col;j++) {
                tran[j][i] = this.Data[i][j];
            }
        }
        Matrix another = new Matrix(this.col,this.row,tran);
        System.out.println("after transpose:");
        return another;

    }

    public String toString() {
        DecimalFormat df = new DecimalFormat("0");
        String result = "";

        //result += df.format(Data[0][0]);
        
        for(int i = 0;i<this.row;i++) {
            result += df.format(Data[i][0]);
            for(int j = 1;j<this.col;j++) {
                result += " " + df.format(Data[i][j]);
            }

            result +=  "\n";
        }
        return result;



    }

}

public class Main{

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int row = scan.nextInt();
        int col = scan.nextInt();
        System.out.println("row:" + row +" column:" + col);

        //set value
        double data[][] = new double[row][col];
        for(int i = 0;i<row;i++) {

            for(int j = 0;j<col;j++) {
                double d = scan.nextDouble();
                data[i][j] = d;

            }
        }
        Matrix matrix = new Matrix(row,col,data);
        int srow = scan.nextInt();
        int scol = scan.nextInt();
        double sv = scan.nextDouble();
        System.out.println("after set value:");
        matrix.setMatrix(srow, scol, sv);
        System.out.print(matrix);
        
        //get value
        DecimalFormat df = new DecimalFormat("0");
        int vrow = scan.nextInt();
        int vcol = scan.nextInt();
        System.out.print("value on (" +vrow + "," + vcol +"):");
        System.out.println(df.format(matrix.getMatrix(vrow, vcol)));

        //add

        int addrow = scan.nextInt();
        int addcol = scan.nextInt();
        double addMatrix[][] = new double[addrow][addcol];
        
        for(int i = 0;i<addrow;i++) {
            for(int j = 0;j<addcol;j++) {
                double ad = scan.nextDouble();
                addMatrix[i][j] = ad;
            }

        }

        Matrix add = new Matrix(addrow,addcol,addMatrix);

        System.out.print(matrix.add(add));
        
//        //mul
        int mulrow = scan.nextInt();

        int mulcol = scan.nextInt();

        double mulMatrix[][] = new double[mulrow][mulcol];

        for(int i = 0;i<mulrow;i++) {

            for(int j = 0;j<mulcol;j++) {
                double mu = scan.nextDouble();
                mulMatrix[i][j] = mu;

            }

        }
        Matrix mul = new Matrix(mulrow,mulcol,mulMatrix);
        //System.out.print(matrix.add(add));
        System.out.print(matrix.multiply(mul));
        //transpose
        System.out.print(matrix.transpose());
    }
}