对最近接近期末的题目集做后的总结性Blog
作者：互联网
一、前言
由于接近期末，我们学习的知识也已经差不多全部完结了，所以我在此对整个学期的知识与pta最后三次作业的知识进行总结。总的来说，后三次作业集是集大成之作，无论是题目难度还是题目量都相较之前都有很大的提高，特别是有关电话计费问题的题目，无论是对我们的编程能力还是结构设计能力都有很大的提高，只不过哦。如果老师还是这样接下去教我们的话，未来会变成什么我不知道，我只知道我在这个学期中所有的知识都是由我自己学来的，和老师好不好，和是不是省级一流课程，和这个学校，和这个学科是不是很高级没有半毛钱关系，都是我自己学来的，所以我觉得这样就可以了。
二、设计与分析
1、题目集08：
总体上来说这是电信计费的起点，所以在类的设计上需要非常小心，不过总的来说为了遵守程序的简洁设计原则，每个类中的属性和方法都不会太多，总的来说都遵守以下的设计，以下是这个题目集乃至之后题目集的总类图：
以下是其中的一些代码（因为实在是太多了）：
class UserRecords{
ArrayList<CallRecord> CallingInCityRecords = new ArrayList<CallRecord>();
ArrayList<CallRecord> CallingInProvinceRecords = new ArrayList<CallRecord>();
ArrayList<CallRecord> CallingInLandRecords = new ArrayList<CallRecord>();
public void addCallingInCityRecords(CallRecord callRecord) {
CallingInCityRecords.add(callRecord);
}
public void addCallingInProvinceRecords(CallRecord callRecord) {
CallingInProvinceRecords.add(callRecord);
}
public void addCallingInLandRecords(CallRecord callRecord) {
CallingInLandRecords.add(callRecord);
}
public ArrayList<CallRecord> getCallingInCityRecords() {
return CallingInCityRecords;
}
public void setCallingInCityRecords(ArrayList<CallRecord> callingInCityRecords) {
CallingInCityRecords = callingInCityRecords;
}
public ArrayList<CallRecord> getCallingInProvinceRecords() {
return CallingInProvinceRecords;
}
public void setCallingInProvinceRecords(ArrayList<CallRecord> callingInProvinceRecords) {
CallingInProvinceRecords = callingInProvinceRecords;
}
public ArrayList<CallRecord> getCallingInLandRecords() {
return CallingInLandRecords;
}
public void setCallingInLandRecords(ArrayList<CallRecord> callingInLandRecords) {
CallingInLandRecords = callingInLandRecords;
}
}
以上的是userrecord类的代码，其中利用了链表的泛型存储各个对象的所有信息。其中大部分类之间的联系是抽象继承。以下是计算在不同区域的电信计费方式的不同类之间的计算。类图和代码如下：
abstract class ChargeRule{
public abstract double CalCost(ArrayList<CallRecord> callRecords) ;
}
abstract class CallChargeRule extends ChargeRule{
public double CalCost(ArrayList<CallRecord> callRecords) {
return 0;
}
}
class LandPhoneInCityRule extends CallChargeRule{
@Override
public double CalCost(ArrayList<CallRecord> callRecords) {
double t = 0;
for(CallRecord a : callRecords) {
double t1 = a.getStartTime().getTime();
double t2 = a.getEndTime().getTime();
t = t+Math.ceil(((t2-t1)/1000.0/60.0))*0.1;
}
return t;
}
}
class LandPhoneInLandRule extends CallChargeRule{
public double CalCost(ArrayList<CallRecord> callRecords) {
double t = 0;
for(CallRecord a : callRecords) {
double t1 = a.getStartTime().getTime();
double t2 = a.getEndTime().getTime();
t = t+Math.ceil(((t2-t1)/1000.0/60.0))*0.6;
}
return t;
}
}
class LandPhoneInProvinceRule extends CallChargeRule{
public double CalCost(ArrayList<CallRecord> callRecords) {
double t = 0;
for(CallRecord a : callRecords) {
double t1 = a.getStartTime().getTime();
double t2 = a.getEndTime().getTime();
t = t+Math.ceil(((t2-t1)/1000.0/60.0))*0.3;
}
return t;
}
}
其中还利用了SimpleDateFormat类的方法，这样在计算两个相隔日期之间的时间时就可以更加准确。
接下来是有关数据的输入与收取问题：
所以正则表达式的编写是非常重要的，不仅在这个题目集在后面两个题目集中也是必须的。题目集08的要求是以下代码的解释：（正则表达式太长，只有后面的部分）
TreeMap<String,User> treeMap = new TreeMap<String,User>();
while(!a.equals("end")) {
String[] s1 = a.split(" ");
if(a.matches(b)) {
String s2 = s1[0].substring(6);
ChargeMode chargeMode = new LandlinePhoneCharging();
User user=new User(s2,chargeMode);
treeMap.put(s2,user);
}
if(a.matches(c))
{
String[] e = a.split("-");
String[] f = e[1].split(" ");
String s3 = s1[0].substring(2,6);
String s4 = s1[1].substring(0,4);
String s5 = f[0].substring(4);
String time1 = s1[2]+" "+s1[3];
String time2 = s1[4]+" "+s1[5];
String q = "079[0-9]|0701";
Date starttime = new Date();
Date endtime = new Date();
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss");
if(treeMap.get(s5)!=null){
try {
starttime = sdf3.parse(time1);//把特点的字符串转成Date的对象
}
catch (ParseException e2) {
e2.printStackTrace();
}
try {
endtime = sdf3.parse(time2);
}
catch (ParseException e1) {
e1.printStackTrace();
}
CallRecord cal = new CallRecord(starttime,endtime,s3,s4);
if(s4.equals(s3)) {
treeMap.get(s5).getUserRecords().addCallingInCityRecords(cal);
}
else if(s4.matches(q)) {
treeMap.get(s5).getUserRecords().addCallingInProvinceRecords(cal);
}
else {
treeMap.get(s5).getUserRecords().addCallingInLandRecords(cal);
}
}
}
a = in.nextLine();
}
for(User user:treeMap.values()) {
System.out.println("0791"+user.getNumber()+" "+user.calCost()+" "+user.calBalance());
}
这就是数据的录入，计算的部分都由后面的类进行。
2、题目集09
不同之处其实只是多加了几个继承的类：
class AnswerPhone extends CallChargeRule{
@Override
public double CalCost(ArrayList<CallRecord> callRecords) {
double s = 0;
for(CallRecord a : callRecords) {
s = s + 0.3*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
return s;
}
}
class CellPhoneCity extends CallChargeRule{
@Override
public double CalCost(ArrayList<CallRecord> callRecords) {
// TODO 自动生成的方法存根
double s = 0;
for(CallRecord a : callRecords) {
if(a.getCallingAddressAreaCode().equals("0791")) {
s = s + 0.1*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
if(a.getCallingAddressAreaCode().matches("079[2-9]|0701|0790")) {
s = s + 0.3*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
else if(!a.getCallingAddressAreaCode().equals("0791")&&!a.getCallingAddressAreaCode().matches("079[0-9]|0701")){
s = s + 0.6*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
}
return s;
}
}
class CellPhoneLand extends CallChargeRule{
@Override
public double CalCost(ArrayList<CallRecord> callRecords) {
// TODO 自动生成的方法存根
double s = 0;
for(CallRecord a : callRecords) {
if(a.getCallingAddressAreaCode().equals("0791")) {
s = s + 0.3*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
if(a.getCallingAddressAreaCode().matches("079[2-9]|0701|0790")) {
s = s + 0.3*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
else if(!a.getCallingAddressAreaCode().equals("0791")&&!a.getCallingAddressAreaCode().matches("079[0-9]|0701")){
s = s + 0.6*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
}
return s;
}
}
class CellPhoneProvince extends CallChargeRule{
@Override
public double CalCost(ArrayList<CallRecord> callRecords) {
// TODO 自动生成的方法存根
double s = 0;
for(CallRecord a : callRecords) {
if(a.getCallingAddressAreaCode().equals("0791")) {
s = s + 0.2*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
if(a.getCallingAddressAreaCode().matches("079[2-9]|0701|0790")) {
s = s + 0.3*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
else if(!a.getCallingAddressAreaCode().equals("0791")&&!a.getCallingAddressAreaCode().matches("079[0-9]|0701")){
s = s + 0.6*Math.ceil((a.getEndTime().getTime()-a.getStartTime().getTime())/1000.0/60.0);
}
}
return s;
}
}
然后就是数据之间的输入与计算：
TreeMap<String,User> treeMap = new TreeMap<String,User>();
while(!a.equals("end")) {
String[] s1 = a.split(" ");
if(a.matches(b)) {
String[] c = a.split("-");
String[] d = c[1].split(" ");
ChargeMode chargeMode = new LandlinePhoneCharging();
User user=new User(d[0],chargeMode);
treeMap.put(d[0],user);
}
if(a.matches(b1)) {
String[] e = a.split("-");
String[] f = e[1].split(" ");
ChargeMode chargeMode = new CellPhoneCharging();
User user=new User(f[0],chargeMode);
treeMap.put(f[0],user);
}
if(a.matches(s3)){ //zj zj
String[] e = a.split("-");
String[] f = e[1].split(" ");
String stime=f[2]+" "+f[3];
String etime=f[4]+" "+f[5];
Date starttime = new Date();
Date endtime = new Date();
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss");
try {
starttime = sdf3.parse(stime);
} catch (ParseException e2) {
e2.printStackTrace();
}
try {
endtime = sdf3.parse(etime);
} catch (ParseException e1) {
e1.printStackTrace();
}
CallRecord cal = new CallRecord(starttime,endtime,f[0].substring(0, 4),f[1].substring(0, 4));
if(treeMap.get(f[0])!=null&&treeMap.size()!=0){
if(f[1].substring(0, 4).equals("0791")) {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInCityRecords(cal);}
}
else if(f[1].substring(0,4).matches(q)) {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInProvinceRecords(cal);}
}
else {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInLandRecords(cal);}
} }
}
if(a.matches(s4)){ //zj sj
String[] e = a.split("-");
String[] f = e[1].split(" ");
String stime=f[3]+" "+f[4];
String etime=f[5]+" "+f[6];
Date starttime = new Date();
Date endtime = new Date();
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss");
try {
starttime = sdf3.parse(stime);
} catch (ParseException e2) {
e2.printStackTrace();
}
try {
endtime = sdf3.parse(etime);
} catch (ParseException e1) {
e1.printStackTrace();
}
CallRecord cal = new CallRecord(starttime,endtime,f[0].substring(0, 4),f[2]);
if(treeMap.get(f[0])!=null&&treeMap.size()!=0){
if(f[2].equals("0791")) {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInCityRecords(cal);}
}
else if(f[2].matches(q)) {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInProvinceRecords(cal);}
}
else {
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addCallingInLandRecords(cal);
}
if(treeMap.get(f[1])!=null){
treeMap.get(f[1]).getUserRecords().addAnswerInLandRecords(cal);
}
}
}
}
3、题目集10
这次题目与其它题目不同之处在于要计算字符的个数，并以此为基础计算费用：
public class Main {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in = new Scanner(System.in);
String a = in.nextLine();
String s111 = "u-1\\d{10}\\s3";
String s21 = "m-1\\d{10}\\s1\\d{10}\\s([a-z]|[A-Z]|[0-9]|[,]|[.]|[ ]){1,}";
TreeMap<String,User> treeMap = new TreeMap<String,User>();
while(!a.equals("end")) {
String[] s1 = a.split(" ");
if(a.matches(s111)) {
String[] e = a.split("-");
String[] f = e[1].split(" ");
User user=new User(f[0],new MessageCharing());
treeMap.put(f[0],user);
}
if(a.matches(s21))
{
String[] e = a.split("-");
String[] f = e[1].split(" ");
String s11 = s1[2];
MessageRecord mes = new MessageRecord(s11);
if(treeMap.get(f[0])!=null){
treeMap.get(f[0]).getUserRecords().addSendMessageRecords(mes);
}
}
a = in.nextLine();
}
for(User user:treeMap.values()) {
System.out.print(user.getNumber()+" ");
System.out.printf("%.1f %.1f\n",user.calCost(),user.calBalance());
}
}
}
abstract class ChargeMode {
ArrayList<ChargeRule> chargeRules = new ArrayList<>();
public ArrayList<ChargeRule> getChargeRules() {
return chargeRules;
}
public void setChargeRules(ArrayList<ChargeRule> chargeRules) {
this.chargeRules = chargeRules;
}
public double calCost(UserRecords userRecords) {
return 0;
}
}
abstract class ChargeRule {
public abstract double calCost(ArrayList<MessageRecord> sendMessageRecords);
}
abstract class CommunicationRecord {
protected String callingNumber;
protected String answeringNumber;
public String getCallingNumber() {
return callingNumber;
}
public void setCallingNumber(String callingNumber) {
this.callingNumber = callingNumber;
}
public String getAnsweringNumber() {
return answeringNumber;
}
public void setAnsweringNumber(String answeringNumber) {
this.answeringNumber = answeringNumber;
}
}
abstract class MessageChargeRule extends ChargeRule{
public double calCost(UserRecords userRecords) {
// TODO 自动生成的方法存根
return 0;
}
}
class MessageCharing extends ChargeMode {
public double calCost(UserRecords userRecords) {
getChargeRules().add(new SendMessageRule());
double abs =0;
double a = super.getChargeRules().get(0).calCost(userRecords.getSendMessageRecords());
abs = a+abs;
return abs;
}
}
class MessageRecord extends CommunicationRecord{
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public MessageRecord(String message) {
super();
this.message = message;
}
}
class SendMessageRule extends ChargeRule{
@Override
public double calCost(ArrayList<MessageRecord> sendMessageRecords) {
// TODO 自动生成的方法存根
int sum = 0;
for(MessageRecord b: sendMessageRecords) {
sum += (int)(Math.ceil(b.getMessage().length()/10.0));
}
if(sum<=3)
return sum*0.1;
else if(sum<=5)
return 0.3+(sum-3)*0.2;
else
return 0.7+(sum-5)*0.3;
}
}
class User{
UserRecords userRecords = new UserRecords();
private double balance = 100 ;
ChargeMode chargemode;
private String number;
public User(String number, ChargeMode chargemode) {
// TODO 自动生成的构造函数存根
this.chargemode=chargemode;
this.number=number;
}
public double getBalance() {
return balance ;
}
public UserRecords getUserRecords() {
return userRecords;
}
public void setUserRecords(UserRecords userRecords) {
this.userRecords = userRecords;
}
public double calBalance() {
return balance-chargemode.calCost(userRecords);
}
public double calCost() {
return chargemode.calCost(userRecords);
}
public ChargeMode getChargemode() {
return chargemode;
}
public void setChargemode(ChargeMode chargemode) {
this.chargemode = chargemode;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
}
class UserRecords{
ArrayList<MessageRecord> sendMessageRecords = new ArrayList<MessageRecord>();
ArrayList<MessageRecord> receiveMessageRecords= new ArrayList<MessageRecord>();
public ArrayList<MessageRecord> getSendMessageRecords() {
return sendMessageRecords;
}
public void setSendMessageRecords(ArrayList<MessageRecord> sendMessageRecords) {
sendMessageRecords = sendMessageRecords;
}
public ArrayList<MessageRecord> getReceiveMessageRecords() {
return receiveMessageRecords;
}
public void setReceiveMessageRecords(ArrayList<MessageRecord> receiveMessageRecords) {
this.receiveMessageRecords = receiveMessageRecords;
}
public void addSendMessageRecords(MessageRecord sendMessageRecord) {
sendMessageRecords.add(sendMessageRecord);
}
public void addReceiveMessageRecords(MessageRecord receiveMessageRecord) {
receiveMessageRecords.add(receiveMessageRecord);
}
}
三、踩坑心得
就拿题目集10的后两个题目来说：要注意内部类与外部类之间的联系，特别是内部类方法的应用要注意。
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int n = input.nextInt();
Shop myshop = new Shop(n);
Shop.InnerCoupons in = myshop.new InnerCoupons(50);
in.setValue(50);
in.buy();
in.setValue(100);
in.buy();
}
}
class Shop {
private int milkCount;
InnerCoupons coupons50;
InnerCoupons coupons100;
public Shop(int milkCount) {
super();
this.milkCount = milkCount;
}
public int getMilkCount() {
return milkCount;
}
public void setMilkCount(int milkCount) {
this.milkCount = milkCount;
}
class InnerCoupons{
public int value;
public InnerCoupons(int value) {
super();
this.value = value;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public void buy() {
System.out.println("使用了面值为"+value+"的购物券进行支付");
int t = Shop.this.getMilkCount();
t = Shop.this.getMilkCount()-value/50;
Shop.this.setMilkCount(t);
System.out.println("牛奶还剩"+t+"箱");
}
}
}
这个即是抽象类的联系
public class Main {
public static void main(String[] args) {
Cat cat = new Cat();
Dog dog = new Dog();
Goat goat = new Goat();
speak(cat);
speak(dog);
speak(goat);
}
//定义静态方法speak()
public static void speak(Animal animal) {
System.out.println(animal.getAnimalClass()+"的叫声："+animal.shout());
}
}
//定义抽象类Animal
abstract class Animal{
public String getAnimalClass() {
return "";
}
public String shout() {
return "";
}
}
//基于Animal类，定义猫类Cat，并重写两个抽象方法
class Cat extends Animal{
public String getAnimalClass() {
return "猫";
}
public String shout() {
return "喵喵";
}
}
//基于Animal类，定义狗类Dog，并重写两个抽象方法
class Dog extends Animal{
public String getAnimalClass() {
return "狗";
}
public String shout() {
return "汪汪";
}
}
//基于Animal类，定义山羊类Goat，并重写两个抽象方法
class Goat extends Animal{
public String getAnimalClass() {
return "山羊";
}
public String shout() {
return "咩咩";
}
}
四、改进建议
我发现在题目08的地方可以把输出改成更加方便的输出：
for(User user:treeMap.values()) {
System.out.println("0791"+user.getNumber()+" "+user.calCost()+" "+user.calBalance());
}
改为：
for(User user:treeMap.values()) {
System.out.println(user.getNumber()+" "+user.calCost()+" "+user.calBalance());
}
这是我发现可以改进的地方。
五、总结
在这个12-15周之间我经历了很多困难和失望，无论是对自己还是这个我待的地方，究竟是哪个地方出现了错误，不过现在这些都不用太过在意，我已经理解了我自己的能力究竟能做到多少，不是因为其它人就是我自己没有学好这门课，我想说的就这么多。
标签：总结性,return,String,集做,treeMap,Blog,ArrayList,new,public 来源： https://www.cnblogs.com/21206119-liuyux/p/16380466.html