140 - 家电类
Description
某大型家电企业拥有一批送货卡车，运送电视机、洗衣机、空调等家电。编程计算每个卡车所装载货物的总重量。
要求有一个Appliance（家电）接口和有三个实现类TV、WashMachine和AirConditioner，这些类能够提供自重。
有一个Truck类，包含了该货车上的所有家电，用一个集合（数组或集合类）表示。
Main函数中程序能够输出Truck类所装载货物的总重量。
Input
家电数量
家电种类编号 家电重量
注意：各个家电的编号为：TV：1 WashMachine：2 AirConditioner：3
Output
总重量
Sample Input
5
1 20
2 30
3 25
3 30
2 40
Sample Output
145
MyAnswer
import java.util.*;
public class Main {
public static void main(String[] args) {
Truck truck = new Truck();
truck.getScan();
System.out.println(truck.getSumWeight());
}
}
interface Appliance{
public int getWeight();
}
class App implements Appliance{
int weight;
public int getWeight(){
return 0;
}
}
class TV extends App implements Appliance{
TV(int w) {
weight=w;
}
@Override
public int getWeight() {
return weight;
}
}
class WashMachine extends App implements Appliance{
WashMachine(int w) {
weight=w;
}
@Override
public int getWeight() {
return weight;
}
}
class AirConditioner extends App implements Appliance{
AirConditioner(int w) {
weight=w;
}
@Override
public int getWeight() {
return weight;
}
}
class Truck{
int num;
App[] app;
int SumWeight;
public void getScan(){
Scanner scan = new Scanner(System.in);
num = scan.nextInt();
app = new App[num];
for(int i=0; i<num; i++){
int type = scan.nextInt();
int w = scan.nextInt();
if(type == 1)
app[i] = new TV(w);
else if(type == 2)
app[i] = new WashMachine(w);
else if(type == 3)
app[i] = new AirConditioner(w);
}
}
public int getSumWeight() {
for(int i=0; i<num; i++){
SumWeight += app[i].getWeight();
}
return SumWeight;
}
}
150 - 教师类
Description
设计一个教师类Teacher,要求：
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。
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。
重写Teacher类的toString方法，通过该方法可以返回“no: **, name:**, age: **, seminary: **”形式的字符串。
Input
两个教师对象的编号，姓名，年龄，学院
Output
教师的信息
两个教师是否相等
Sample Input
1 Linda 38 SoftwareEngineering
2 Mindy 27 ComputerScience
Sample Output
no: 1, name:Linda, age: 38, seminary: SoftwareEngineering
no: 2, name:Mindy, age: 27, seminary: ComputerScience
false
MyAnswer
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int n1 = scan.nextInt();
String na1 = scan.next();
int a1 = scan.nextInt();
String s1 = scan.next();
Teacher t1 = new Teacher(n1,na1,a1,s1);
int n2 = scan.nextInt();
String na2 = scan.next();
int a2 = scan.nextInt();
String s2 = scan.next();
Teacher t2 = new Teacher(n2,na2,a2,s2);
System.out.println(t1.toString());
System.out.println(t2.toString());
System.out.println(t1.equals(t2));
}
}
class Teacher{
int no;
String name;
int age;
String seminary;
Teacher(int no, String name, int age, String seminary){
setNo(no);
setName(name);
setSeminary(seminary);
setAge(age);
}
public void setNo(int no) {
this.no = no;
}
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public void setSeminary(String seminary) {
this.seminary = seminary;
}
public String getName() {
return name;
}
public int getNo() {
return no;
}
public int getAge() {
return age;
}
public String getSeminary() {
return seminary;
}
public boolean equals(Object o){
if(o == null)
return false;
else{
boolean res = false;
if(o instanceof Teacher){
Teacher t = (Teacher)o;
if(this.no == t.no){
res = true;
}
}
return res;
}
}
public String toString(){
return "no: "+getNo()+", name:"+getName()+", age: "+getAge()+", seminary: "+getSeminary();
}
}
149 - 教师类-2
Description
修改题目143
1. 修改教师类，使得由多个Teacher对象所形成的数组可以排序（编号由低到高排序），并在main函数中使用Arrays.sort(Object[] a)方法排序
2. 定义一个类TeacherManagement，包含教师数组，提供方法add(Teacher[])，使其可以添加教师，提供重载方法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：“no: **, name:**, age: **, seminary: **”。如果没有满足条件的教师，则返回“no such teacher”。
Input
教师个数
教师信息
待查找教师的姓名
待查找教师的年龄
Output
排序后的信息
按姓名查找的老师信息
按年龄查找的老师信息
Sample Input
4
3 Linda 38 SoftwareEngineering
1 Mindy 27 ComputerScience
4 Cindy 28 SoftwareEngineering
2 Melody 27 ComputerScience
Cindy
27
Sample Output
no: 1, name: Mindy, age: 27, seminary: ComputerScience
no: 2, name: Melody, age: 27, seminary: ComputerScience
no: 3, name: Linda, age: 38, seminary: SoftwareEngineering
no: 4, name: Cindy, age: 28, seminary: SoftwareEngineering
search by name:
no: 4, name: Cindy, age: 28, seminary: SoftwareEngineering
search by age:
no: 1, name: Mindy, age: 27, seminary: ComputerScience
no: 2, name: Melody, age: 27, seminary: ComputerScience
MyAnswer
import java.util.*;
import java.lang.reflect.Array;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int i;
int num = scan.nextInt();
TeacherManagement tm = new TeacherManagement(num);
Teacher[] t = new Teacher[num];
for(i=0; i<num; i++){
int no = scan.nextInt();
String name = scan.next();
int age = scan.nextInt();
String sem = scan.next();
t[i] = new Teacher(no,name,age,sem);
}
tm.add(t);
Arrays.sort(t);
for(i=0;i<t.length;i++){
System.out.println(t[i].toString());
}
String s1 = scan.next();
tm.search(s1);
int s2 = scan.nextInt();
tm.search(s2);
}
}
class Teacher implements Comparable<Teacher>{
int no;
String name;
int age;
String seminary;
Teacher(int no, String name, int age, String seminary){
setNo(no);
setName(name);
setSeminary(seminary);
setAge(age);
}
public void setNo(int no) {
this.no = no;
}
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public void setSeminary(String seminary) {
this.seminary = seminary;
}
public String getName() {
return name;
}
public int getNo() {
return no;
}
public int getAge() {
return age;
}
public String getSeminary() {
return seminary;
}
public boolean equals(Object o){
if(o == null)
return false;
else{
boolean res = false;
if(o instanceof Teacher){
Teacher t = (Teacher)o;
if(this.no == t.no){
res = true;
}
}
return res;
}
}
public String toString(){
return "no: "+getNo()+", name: "+getName()+", age: "+getAge()+", seminary: "+getSeminary();
}
public int compareTo(Teacher t){
if(this.no == t.no)
return 0;
else if(this.no>t.no)
return 1;
else
return -1;
}
}
class TeacherManagement{
Teacher[] t;
int num;
TeacherManagement(int num){
this.num = num;
this.t = new Teacher[num];
}
public void add(Teacher[] t){
this.t = t;
}
// 重载
public void search(int age){
int flag = 0;
System.out.println("search by age:");
for (Teacher aT : t) {
if (aT.age == age) {
flag = 1;
System.out.println(aT.toString());
}
}
if(flag==0){
System.out.println("no such teacher");
}
}
public void search(String name){
int flag = 0;
System.out.println("search by name:");
for (Teacher aT : t) {
if (aT.name.equals(name)) {
flag = 1;
System.out.println(aT.toString());
}
}
if(flag==0){
System.out.println("no such teacher");
}
}
}
142 - 计算机类
Description
构造计算机类，其中包含其配置信息：处理器、主板、内存、显示器、硬盘等设备，各个设备均有型号（字符串），
特别的，处理器有主频（小数）和内核数（整数）、显示器有尺寸（整型）、内存和硬盘有容量数据（GB为单位）。
请你尝试构造合适的类和类的关系来表示计算机，并为该计算机类添加计算价格（各设备价格之和）、打印配置信息等方法。
重写相关类的equals方法，使得两个配置完全相同的计算机为相同的计算机。重写相关类的toString函数，打印计算机的配置信息。
在main函数中
Input
两个计算机对象，包含
CPU：型号、主频、内核
主板：型号
内存：容量
显示器：尺寸
硬盘：容量
Output
两个对象是否相等
两个对象的配置信息
Sample Input
Corei7 2.8 4
GIGABYTE-B250M-D3H
xiede-DDR3 8
SamsungC27F39 27
SEAGATE-ST1000DM010 2048
Corei7 2.8 4
GIGABYTE-B250M-D3H
xiede-DDR3 8
SamsungC27F39 27
SEAGATE-ST1000DM010 2048
Sample Output
true
Computer1:
CPU:
Model: Corei7
Frequency: 2.8
Number of Cores: 4
Mainboard:
Model: GIGABYTE-B250M-D3H
Memory:
Model: xiede-DDR3
Size: 8
Screen:
Model: SamsungC27F39
Size: 27
Harddisk:
Model: SEAGATE-ST1000DM010
Size: 2048
Computer2:
CPU:
Model: Corei7
Frequency: 2.8
Number of Cores: 4
Mainboard:
Model: GIGABYTE-B250M-D3H
Memory:
Model: xiede-DDR3
Size: 8
Screen:
Model: SamsungC27F39
Size: 27
Harddisk:
Model: SEAGATE-ST1000DM010
Size: 2048
HINT
为计算机类和各个组成配件都构造类，分别重写toString和equals方法
在计算机类中调用各个配件的equals和toString方法
回车用\n
小数用String.format("%.1f",1.234)
MyAnswer
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String cModel = scan.next();
String cFrequency = scan.next();
int cNumofCores = scan.nextInt();
String mModel = scan.next();
String meModel = scan.next();
int meSize = scan.nextInt();
String sModel = scan.next();
int sSize = scan.nextInt();
String hModel = scan.next();
int hSize = scan.nextInt();
CPU cpu1 = new CPU(cModel,cFrequency,cNumofCores);
MainBoard mb1 = new MainBoard(mModel);
Memory mem1 = new Memory(meModel,meSize);
Screen sc1 = new Screen(sModel,sSize);
Harddisk hd1 = new Harddisk(hModel,hSize);
Computer cp1 = new Computer(cpu1,mb1,mem1,sc1,hd1);
cModel = scan.next();
cFrequency = scan.next();
cNumofCores = scan.nextInt();
mModel = scan.next();
meModel = scan.next();
meSize = scan.nextInt();
sModel = scan.next();
sSize = scan.nextInt();
hModel = scan.next();
hSize = scan.nextInt();
CPU cpu2 = new CPU(cModel,cFrequency,cNumofCores);
MainBoard mb2 = new MainBoard(mModel);
Memory mem2 = new Memory(meModel,meSize);
Screen sc2 = new Screen(sModel,sSize);
Harddisk hd2 = new Harddisk(hModel,hSize);
Computer cp2 = new Computer(cpu2,mb2,mem2,sc2,hd2);
System.out.println(cp1.equals(cp2));
System.out.println("Computer1:");
System.out.println(cp1);
System.out.println("Computer2:");
System.out.println(cp2);
}
}
class Father{
String model;
Father(String model){
this.model = model;
}
}
class CPU extends Father{
String freq;
int numCores;
public CPU(String model, String freq,int numCores){
super(model);
this.freq = freq;
this.numCores = numCores;
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof CPU){
CPU c = (CPU) o;
return this.model.equals(c.model) && this.freq.equals(c.freq) && this.numCores == c.numCores;
}
else
return false;
}
public String toString(){
return "CPU:\nModel: " + model + "\nFrequency: " +freq +"\nNumber of Cores: " + numCores + "\n";
}
}
class MainBoard extends Father{
MainBoard(String model){
super(model);
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof MainBoard){
MainBoard mb = (MainBoard) o;
return this.model.equals(mb.model);
}
else
return false;
}
public String toString(){
return "Mainboard:\nModel: "+model+"\n";
}
}
class Memory extends Father{
int size;
Memory(String model, int size){
super(model);
this.size = size;
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof Memory){
Memory m = (Memory) o;
return this.model.equals(m.model) && this.size == m.size;
}
else
return false;
}
public String toString(){
return "Memory:\nModel: "+model+"\nSize: "+size+"\n";
}
}
class Screen extends Father{
int size;
Screen(String model, int size){
super(model);
this.size = size;
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof Screen){
Screen s = (Screen) o;
return this.model.equals(s.model) && this.size == s.size;
}
else
return false;
}
public String toString(){
return "Screen:\nModel: "+model+ "\nSize: "+size+"\n";
}
}
class Harddisk extends Father{
int size;
Harddisk(String model, int size){
super(model);
this.size = size;
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof Harddisk){
Harddisk h = (Harddisk) o;
return this.model.equals(h.model) && this.size == h.size;
}
else
return false;
}
public String toString(){
return "Harddisk:\nModel: "+model+ "\nSize: "+size;
}
}
class Computer{
CPU cpu;
MainBoard mainboard;
Memory memory;
Screen screen;
Harddisk harddisk;
Computer(CPU cpu,MainBoard mainboard,Memory memory,Screen screen,Harddisk harddisk){
this.cpu = cpu;
this.mainboard = mainboard;
this.memory = memory;
this.screen = screen;
this.harddisk = harddisk;
}
public boolean equals(Object o){
if(o==null) return false;
else if(o instanceof Computer){
Computer c = (Computer) o;
return this.cpu.equals(c.cpu) && this.mainboard.equals(c.mainboard) && this.memory.equals(c.memory) && this.screen.equals(c.screen) && this.harddisk.equals(c.harddisk);
}
else
return false;
}
public String toString() {
return cpu.toString() + mainboard.toString() + memory.toString() + screen.toString() + harddisk.toString();
}
}
139 - 整数数组比较
Description
给定两个整型数组A和B，将A的元素复制到B中，使得两个数组完全相同。再将B数组从小到大排列，将两数组的同一位
置上对应的元素进行比较，统计出A中大于B的元素个数，等于B中元素的个数，小于B中的元素的个数。
Input
数组A的个数
数组A元素
Output
A大于B的个数
A等于B的个数
A小于B的个数
Sample Input
10
23 1 32 87 65 12 21 9 76 45
Sample Output
4
1
5
HINT
可用Arrays.sort排序
MyAnswer
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int num = scan.nextInt();
int[] a = new int[num];
int i;
int bigger=0,smaller=0,equal=0;
for(i=0; i<num; i++){
a[i] = scan.nextInt();
}
int b[] = a.clone();
Arrays.sort(b);
for(i=0; i<num; i++){
if(a[i] > b[i])
bigger++;
else if(a[i]==b[i])
equal++;
else
smaller++;
}
System.out.println(bigger);
System.out.println(equal);
System.out.println(smaller);
}
}
151 - 矩阵类
Description
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）toString()：以行和列的形式打印出当前矩阵。
Input
矩阵的行列数
矩阵的数据
设置矩阵值的行、列和值
获取矩阵值的行、列
待相加矩阵的行列数
待相加矩阵的值
待相乘矩阵的行列数
待相乘矩阵的值
Output
矩阵的行、列数
设置矩阵值后的矩阵
某行某列的矩阵值
矩阵相加结果
矩阵相乘结果
矩阵转置结果
Sample Input
3 3
1 2 3
4 5 6
7 8 9
2 3 8
1 3
3 3
1 2 3
4 5 6
7 8 9
3 2
1 2
1 2
1 2
Sample Output
row:3 column:3
after set value:
1 2 3
4 5 8
7 8 9
value on (1,3):3
after add:
2 4 6
8 10 14
14 16 18
after multiply:
6 12
17 34
24 48
after transpose:
1 4 7
2 5 8
3 8 9
MyAnswer
import java.rmi.MarshalException;
import java.util.*;
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);
Matrix matrix = new Matrix(row,col);
for(int i=0; i<row; i++){
for (int j = 0; j < col; j++) {
double t = scan.nextDouble();
matrix.set(i,j,t);
}
}
System.out.println("after set value:");
int m = scan.nextInt();
int n = scan.nextInt();
double p = scan.nextDouble();
matrix.set(m-1,n-1,p);
System.out.println(matrix);
m = scan.nextInt();
n = scan.nextInt();
System.out.println("value on (" + m + "," + n + "):" + (int)matrix.get(m - 1,n - 1));
System.out.println("after add:");
m = scan.nextInt();
n = scan.nextInt();
Matrix matrix2 = new Matrix(m,n);
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
double t = scan.nextDouble();
matrix2.set(i,j,t);
}
}
System.out.println(matrix2.add(matrix));
System.out.println("after multiply:");
m = scan.nextInt();
n = scan.nextInt();
Matrix matrix3 = new Matrix(m,n);
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
double t = scan.nextDouble();
matrix3.set(i,j,t);
}
}
System.out.println(matrix.multiply(matrix3));
System.out.println("after transpose:");
System.out.println(matrix.transpose());
scan.close();
}
}
class Matrix{
int row;
int col;
double a[][];
public Matrix(int r, int c){
row = r;
col = c;
a = new double[row][col];
}
public int getRow(){
return row;
}
public int getCol(){
return col;
}
public void set(int r, int c, double value){
this.a[r][c] = value;
}
public double get(int r, int c){
return this.a[r][c];
}
public Matrix add(Matrix b){
for(int i=0; i<b.getRow(); i++){
for(int j=0; j<b.getCol(); j++){
double tmp=0;
tmp += this.get(i,j) + b.get(i,j);
this.set(i,j,tmp);
}
}
return this;
}
public Matrix multiply(Matrix b){
Matrix c = new Matrix(this.getRow(),b.getCol());
for(int i=0; i<this.getRow(); i++){
for(int j=0; j<b.getCol(); j++){
double tmp=0;
for(int k=0; k<this.getCol(); k++){
tmp += this.get(i,k)*b.get(k,j);
}
c.set(i,j,tmp);
}
}
return c;
}
public Matrix transpose(){
for(int i=0; i<this.getRow(); i++){
for(int j=0; j<i; j++){
double tmp = this.get(i,j);
this.set(i,j,this.get(j,i));
this.set(j,i,tmp);
}
}
return this;
}
public String toString(){
String s = "";
for(int i=0; i<row; i++){
for(int j=0; j<col; j++){
if(j != 0)
s += " ";
int tmp = (int)this.get(i,j);
s += tmp;
}
if(i != row-1)
s += "\n";
}
return s;
}
}
