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4-5题目集及期中

时间：2023-06-30 20:11:07浏览次数：45  
标签：count 题目 int double 期中 Integer parseInt table 集及

前言：

第四次题目集的知识点涉及Time类以及前面学的各种知识点；题量很少只有一题；难度比较大。第五次题目集的知识点主要是Time类、异常处理等等；题量很少只有一题；难度比较大。期中考试的知识点涉及类、继承与多态、接口等等；题量不多，一共4题；整体难度不高。

第四次题目集

7-1 菜单计价程序-4

我的类图：

 

 我的代码：

 

import java.time.YearMonth;
import java.util.Calendar;
import java.util.Objects;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Menu menu = new Menu();
        Table[] table = new Table[57];//桌号1-55；
        int j = 0;//菜单数
        int l = 0;//订单数
        //代点菜数
        //遍历桌
        int cntTab = 0;//桌号
        String[] temp;//字符串存储
        int tempordernum = 0;//临时存上一个有效序号
        String input;
        String regex = "[\\u4e00-\\u9fa5]* \\d*";//非特色菜菜谱
        String regex1 = "[\\u4e00-\\u9fa5]* \\d* T";//特色菜谱
        String regex2 = "\\d (delete)";//删除情况
        String regex3 = "(table) ([1-4][0-9]*|5[0-5]*) \\d{4}/\\d+/\\d{1,2} ([0-1]?[0-9]|2[0-3])/([0-5][0-9])/([0-5][0-9])";//添桌子的情况
        String regex4 = "([1-9]|[1-9][0-9]*) [\\u4e00-\\u9fa5]+ \\d+ \\d+";//点菜记录的添加；
        String regex5 = "([1-4][0-9]*|5[0-5]*|[1-9]) \\d [\\u4e00-\\u9fa5]+ [123] (1[0-5]|[1-9])";//代点菜
 
        while (true) {
            int count;//空格数量；
            input = sc.nextLine();//获取输入，每行
            if(input.equals("end"))
                break;
            if(input.equals("")) {
                System.out.println("wrong format");
                continue;
            }
            temp = input.split(" ");//分割
            /*
             * 判断输入的类型*/
            count = temp.length;
            if(count==2){//非特色菜菜谱，或者删除菜；
                if(input.matches(regex2)){//删除的情况桌子有效才删除
                    if (table[cntTab] == null) throw new AssertionError();
                    if(table[cntTab].inputIsvalid){
                        table[cntTab].order.delARecordByOrderNum(Integer.parseInt(temp[0]));//删除
 
                    }
                }else if(input.matches(regex)){//非特色菜谱添加
                    if (cntTab == 0) {
                        menu.dishes[j] = new Dish();
                        //menu.dishes[j] = menu.addDish(temp[0], Integer.parseInt(temp[1]));
                        j++;
                    } else if(table[cntTab].inputIsvalid){
                        System.out.println("invalid dish");
                    }
 
                }else {
                    System.out.println("wrong format");
                }
            }else if(count==3){//特色菜菜谱
                if(input.matches(regex1)) {
                    if(cntTab!=0) {
                        if(table[cntTab].inputIsvalid)
                            System.out.println("invalid dish");
                        else
                            continue;
                    }
 
                    menu.dishes[j] = new Dish();
                    //menu.dishes[j] = menu.addDish(temp[0], Integer.parseInt(temp[1]));
                    menu.dishes[j].isSpecial = true;//是特色菜
                    j++;
                }else
                    System.out.println("wrong format");
            }
            //桌子的添加，点菜记录的添加，
            else if(temp[0].equals("table")||input.contains("/")) {
                cntTab++;
                table[cntTab] = new Table();
                if(temp[0].equals("table")){
                    if(input.matches(regex3))
                        table[cntTab].AheadProcess(input);
                    table[cntTab].inputIsvalid=true;
                    if (input.matches(regex3)) {
                        if(table[cntTab].inputIsvalid&&!table[cntTab].DateisValid()){//检查日期
                            System.out.println(table[cntTab].tableNum+" date error");
                            table[cntTab].inputIsvalid=false;
                            continue;
                        }
                        if(table[cntTab].inputIsvalid&&!table[cntTab].Daterande()){
                            table[cntTab].inputIsvalid=false;
                            continue;
                        }
                        for(int i =1;i<cntTab;i++){
                            if (table[i].inputIsvalid && table[cntTab].CheckSameTime(table[i])) {//同一时间段
                                table[cntTab].istoSum = true;
                            } else {
                                l = 0;
                            }
                            tempordernum = 0;
                        }
                        if(table[cntTab].discnt>0)
                            System.out.println("table " + table[cntTab].tableNum + ": ");
                        else {
                            System.out.println("table " + table[cntTab].tableNum + " out of opening hours");
                            table[cntTab].inputIsvalid = false;
                        }
                        continue;
                    } else {//第一个是table但不合法
                        table[cntTab].inputIsvalid = false;
                        if(!temp[1].equals("")&&temp[1].charAt(0)>='1'&&temp[1].charAt(0)<='9'&&!temp[1].contains("/")){
                            if(Integer.parseInt(temp[1])<1||Integer.parseInt(temp[1])>55){
                                System.out.println(Integer.parseInt(temp[1])+" table num out of range");
                                continue;
                            }
                        }
                    }
                }
                System.out.println("wrong format");
                table[cntTab].inputIsvalid = false;
                if(!temp[0].equals("table"))
                    table[cntTab].istoSum = true;
 
            }else if(count==4){
                if(input.matches(regex4)&&(Objects.requireNonNull(table[cntTab]).inputIsvalid||table[cntTab].istoSum)){//点菜记录
                    Dish tem;
                    int aheadcntTab = cntTab-1;
                    if(!table[cntTab].istoSum) {//不需要合并
                        table[cntTab].order.records[l] = new Record();
                        table[cntTab].order.records[l] = table[cntTab].order.addARecord(Integer.parseInt(temp[0]), temp[1], Integer.parseInt(temp[2]), Integer.parseInt(temp[3]));
                        if(l-1>=0){//判断记录序号是否递增
                            tempordernum = getTempordernum(table, l, temp, tempordernum, cntTab);
                        }else {//特殊情况
                            if(table[cntTab].order.records[l].Checkahead())
                                tempordernum = table[cntTab].order.records[l].orderNum;
                        }
                        if((tem = menu.searchDish(temp[1]))!=null){
                            float temdiscnt;//临时储存折扣
                            table[cntTab].order.records[l].d = tem;
                            temdiscnt = table[cntTab].order.records[l].Checkportion(table[cntTab].discnt);
                            if(temdiscnt!=1F)
                                table[cntTab].rediscnt = temdiscnt;//最终折扣
                            if(table[cntTab].order.records[l].exist==1&&table[cntTab].order.records[l].noNeed) {
                                if(table[cntTab].rediscnt!=1) {
                                    table[cntTab].sum += Math.round(table[cntTab].order.records[l].getPrice() * table[cntTab].rediscnt);
                                    table[cntTab].rediscnt=1.0F;
                                }
                                else
                                    table[cntTab].sum += Math.round(table[cntTab].order.records[l].getPrice() * table[cntTab].discnt);
                            }
                        }
 
                        if(!table[cntTab].istoSum){//如果份额名字未重复；
                            l++;
                        }
                    } else{//需要合并计算
                        table[aheadcntTab].order.records[l] = new Record();
                        table[aheadcntTab].order.records[l] = table[aheadcntTab].order.addARecord(Integer.parseInt(temp[0]), temp[1], Integer.parseInt(temp[2]), Integer.parseInt(temp[3]));
                        if(l-1>=0){//判断记录序号是否递增
                            tempordernum = getTempordernum(table, l, temp, tempordernum, aheadcntTab);
                        }
                        if((tem = menu.searchDish(temp[1]))!=null){
                            float temdiscnt;//临时储存折扣
                            table[aheadcntTab].order.records[l].d = tem;
                            temdiscnt = table[aheadcntTab].order.records[l].Checkportion(table[aheadcntTab].discnt);//计算折扣
                            if(temdiscnt==0.7F)//如果需要调整
                                table[aheadcntTab].rediscnt = temdiscnt;//最终折扣//更改折扣
                            if(table[aheadcntTab].order.records[l].exist==1) {//必须存在
                                if(table[aheadcntTab].rediscnt!=1) {
                                    table[aheadcntTab].sum += Math.round(table[aheadcntTab].order.records[l].getPrice() * table[aheadcntTab].rediscnt);
                                    table[aheadcntTab].rediscnt=1.0F;
                                }
                                else
                                    table[aheadcntTab].sum += Math.round(table[aheadcntTab].order.records[l].getPrice() * table[cntTab].discnt)-1;
                            }
                        }
 
                        l++;
                    }
 
                }else {
                    if(table[cntTab]==null) {
                        System.out.println("wrong format");
                        continue;
                    }
                    if(table[cntTab]!=null&&table[cntTab].inputIsvalid)
                        System.out.println("wrong format");
                }
            }
            else if(count==5&& Objects.requireNonNull(table[cntTab]).inputIsvalid){//代点菜
                int temSum = 0;
                if(input.matches(regex5)){
                    int AnothNum = Integer.parseInt(temp[0]);
                    table[cntTab].order.records[l] = table[cntTab].order.takeorderfor(table[cntTab].tableNum,table,AnothNum,Integer.parseInt(temp[1]),temp[2],Integer.parseInt(temp[3]),Integer.parseInt(temp[4]));
                    Dish tem;
                    if((tem = menu.searchDish(temp[2]))!=null&&table[cntTab].order.records[l]!=null){
                        table[cntTab].order.records[l].isTaked = true;//给别人diade
                        float temdiscnt;//临时储存折扣
                        table[cntTab].order.records[l].d = tem;
                        temdiscnt = table[cntTab].order.records[l].Checkportion(table[cntTab].discnt);
                        if(temdiscnt!=1F)
                            table[cntTab].rediscnt = temdiscnt;//最终折扣
                        if(table[cntTab].order.records[l].exist==1&&table[cntTab].order.records[l].noNeed) {
                            if(table[cntTab].rediscnt!=1) {
                                table[cntTab].sum += Math.round((temSum=table[cntTab].order.records[l].getPrice()) * table[cntTab].rediscnt);
                                table[cntTab].rediscnt=1.0F;
                            }
                            else
                                table[cntTab].sum +=  Math.round((temSum =table[cntTab].order.records[l].getPrice()) * table[cntTab].discnt);
                        }
                        System.out.println(temp[1] + " table " + table[cntTab].tableNum + " pay for table " + temp[0] + " " + temSum);
                    }
                    if(table[cntTab].order.records[l]!=null)
                        l++;
                }else
                    System.out.println("wrong format");
 
            }else{
                assert table[cntTab] != null;
                if(table[cntTab].inputIsvalid)
                    System.out.println("wrong format");
            }
        }
        for(int i=1;i<=cntTab;i++){
            if(table[i].inputIsvalid&&!table[i].istoSum)
                table[i].GetTotalPrice();
        }
 
    }
 
    private static int getTempordernum(Table[] tablemes, int l, String[] temp, int tempordernum, int aheadcntTab) {
        if(Integer.parseInt(temp[0])<=tempordernum) {
            System.out.println("record serial number sequence error");
            tablemes[aheadcntTab].order.records[l].exist=0;
        }else
        if(tablemes[aheadcntTab].order.records[l]!=null&&tablemes[aheadcntTab].order.records[l].noNeed)
            tempordernum = tablemes[aheadcntTab].order.records[l].orderNum;
        return tempordernum;
    }
}
 
 
class Dish {
    String name; // 菜品名称
    boolean isSpecial = false; // 是不是特色菜
    int unit_price; // 单价
    boolean exist = true;
 
    int getPrice(int portion) {
        int price0;
        switch (portion) {
            case 1:
                price0 = unit_price;
                break;
            case 2:
                price0 = Math.round((float) (unit_price * 1.5));
                break;
            case 3:
                price0 = unit_price * 2;
                break;
            default:
                throw new IllegalArgumentException("Invalid portion: " + portion);
        }
        return price0;
    }
 
 
    // 构造方法
    public Dish() {
    }
 
}
 
class Menu {
    Dish[] dishes = new Dish[10];
    int count = 0;
    Dish searchDish(String dishName) {
        for (int i = 0; i < count; i++) {
            Dish dish = dishes[i];
            if (dishName.equals(dish.name) && dish.exist) {
                return dish;
            }
        }
        System.out.println(dishName + " does not exist");
        return null;
    }
 
   /* Dish addDish(String dishName, int unitPrice) {
        if (unitPrice < 1 || unitPrice > 300) {
            System.out.println(dishName + " price out of range " + unitPrice);
            return null;
        }
        Dish dish = new Dish();
        dish.name = dishName;
        dish.unit_price = unitPrice;
        dishes[count++] = dish;
        return dish;
    }
    */
    
}
 
class Record {
    int orderNum;
    Dish d = new Dish();
    int num = 0;
    int portion;
    boolean noNeed = true;
    int exist = 1;
    float realDiscount = 1;
    boolean isTaked = false;
 
    int getPrice() {
        return Math.round(d.getPrice(portion) * num);
    }
 
    float Checkportion(float discount) {
        if (portion < 1 || portion > 3) {
            System.out.println(orderNum + " portion out of range " + portion);
            exist = 0;
            noNeed = false;
        } else if (num < 1 || num > 15) {
            System.out.println(orderNum + " num out of range " + num);
            exist = 0;
            noNeed = false;
        } else {
            if (d.isSpecial && (discount == 0.8F || discount == 0.6F)) {
                realDiscount = 0.7F;
            }
            if (exist == 1 && !isTaked) {
                System.out.println(orderNum + " " + d.name + " " + getPrice());
            }
        }
        return realDiscount;
    }
 
    boolean Checkahead() {
        return num >= 1 && num <= 15 && portion >= 1 && portion <= 3;
    }
}
class Order {
    Record[] records = new Record[100];
    private int count = 0;
 
    public int getTotalPrice() {
        int sum = 0;
        for (int i = 0; i < count; i++) {
            Record record = records[i];
            if (record != null && record.exist == 1) {
                sum += record.getPrice();
            }
        }
        return sum;
    }
 
    public Record addARecord(int orderNum, String dishName, int portion, int num) {
        int index = -1;
        for (int i = 0; i < count; i++) {
            Record record = records[i];
            if (record != null && record.d.name.equals(dishName) && record.portion == portion) {
                index = i;
                break;
            }
        }
        if (index == -1) {
            Record record = new Record();
            record.d.name = dishName;
            record.orderNum = orderNum;
            record.portion = portion;
            record.num = num;
            records[count++] = record;
            return record;
        } else {
            return records[index];
        }
    }
 
    public Record takeorderfor(int mynum, Table[] tables, int anotherNum, int orderNum, String dishName, int portion, int num) {
        boolean flag = false;
        for (Table table : tables) {
            if (table != null && table.tableNum != mynum && table.tableNum == anotherNum) {
                flag = true;
                break;
            }
        }
        if (flag) {
            return addARecord(orderNum, dishName, portion, num);
        } else {
            System.out.println("Table number: " + anotherNum + " does not exist");
            return null;
        }
    }
 
    public void delARecordByOrderNum(int orderNum) {
        if (orderNum > count || orderNum <= 0) {
            System.out.println("Delete error");
            return;
        }
        Record record = records[orderNum - 1];
        if (record.exist == 0) {
            System.out.println("Deduplication " + orderNum);
            return;
        }
        record.exist = 0;
    }
}
 
class Table {
    int tableNum;
    boolean inputIsvalid = false;
    boolean istoSum = false;
    String tableDtime;
    int year, month, day, week, hh, mm, ss;
    int sum = 0;
    int primesum = 0;
    Order order = new Order();
    float discnt = -1;
    float rediscnt = 1;
    void GetTotalPrice() {
        if (discnt > 0) {
            primesum = order.getTotalPrice();
            if (primesum == 0)
                sum = 0;
            System.out.println("table " + tableNum + ": " + primesum + " " + sum);
        }
    }
 
    void AheadProcess(String tableDtime) {
        this.tableDtime = tableDtime;
        processTime();
        discount();
    }
 
    void processTime() {
        String[] temp = tableDtime.split(" ");
        tableNum = Integer.parseInt(temp[1]);
        String[] temp1 = temp[2].split("/");
        String[] temp2 = temp[3].split("/");
 
        year = Integer.parseInt(temp1[0]);
        month = Integer.parseInt(temp1[1]);
        day = Integer.parseInt(temp1[2]);
 
        Calendar c = Calendar.getInstance();
        c.set(year, (month - 1), day);
        week = c.get(Calendar.DAY_OF_WEEK);
        if (week == 1)
            week = 7;
        else
            week--;
 
        hh = Integer.parseInt(temp2[0]);
        mm = Integer.parseInt(temp2[1]);
        ss = Integer.parseInt(temp2[2]);
    }
 
    boolean DateisValid() {
        if (year < 1000)
            return false;
        if (month < 1 || month > 12)
            return false;
        YearMonth mytime = YearMonth.of(year, month);
        return mytime.isValidDay(day);
    }
 
    boolean Daterande() {
        boolean flag = true;
        if (year < 2022 || year > 2023) {
            flag = false;
        }
        if (!flag) {
            System.out.println("not a valid time period");
            inputIsvalid = false;
        }
        return flag;
 
    }
 
    void discount() {
        if (week >= 1 && week <= 5) {
            if (hh >= 17 && hh < 20 || (hh == 20 && mm < 30)) {
                discnt = 0.8F;
            } else if ((hh >= 11 && hh <= 13) || (hh == 10 && mm >= 30) || (hh == 14 && mm < 30)) {
                discnt = 0.6F;
            } else {
                discnt = 1.0F;
            }
        } else {
            if (hh >= 10 && hh <= 20 || (hh == 9 && mm >= 30) || (hh == 21 && mm < 30)) {
                discnt = 1.0F;
            } else {
                discnt = 1.0F;
            }
        }
    }
 
    boolean CheckSameTime(Table table) {
        if (tableNum != table.tableNum)
            return false;
        if (week == table.week && week >= 1 && week <= 5) {
            return discnt == table.discnt;
        } else if (week == table.week && (week == 6 || week == 7)) {
            int subtime = hh * 3600 + mm * 60 + ss - table.hh * 3600 - table.mm * 60 -ss;
            return Math.abs(subtime) < 3600;
        }
        return false;
    }
}

 

我的分析：

这次题目难度提升了很多，应该要将每个模块的功能限制在一个特定的任务上，这样可以提高代码的可读性和可维护性。使用有意义的变量和方法名称，确保变量和方法的名称能够清晰地描述其用途。避免使用简单的字母和数字作为名称。还可以简化正则表达式，简化代码中的正则表达式，使其更易于理解和维护。可以将这些值保存在常量中，并使用常量来表示它们，这样可以提高代码的可扩展性和可维护性。

第五次题目集

 

我的类图：

 

 我的代码：

 

import java.util.Calendar;
import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Order[] order = new Order[10];
        Menu menu = new Menu();
        String[] count;
        int flag;
        int j = 0;
 
        int end = 0;//当遇到end结束时
 
        String[] list = new String[10];//记录不同菜系判断口味度需要， 川菜的
        String[] list1 = new String[10];//记录不同菜系判断口味度需要， 晋菜的
        String[] list2 = new String[10];//记录不同菜系判断口味度需要， 浙菜的
 
        int[] num = new int[20];
        /*
        记录每道菜菜系的不同
        * 用0代表普通菜
        * 用1代表川菜
        * 用2代表晋菜
        * 用3代表浙菜
        */
 
        int[] number = new int[20];//计算有效点单
        int[] table_num = new int[10];//记录桌号的数组
 
        int flag1 = 0;//记录有效菜单的个数
        int flag2 = 0;//当点特色菜的的时候
        int flag3 = 0;//记录符合特价菜时间的折扣的标记点
        /*
        * flag3 = 1代表是特价菜7折，代表是普通6折
        * flag3 = 2代表是特价菜7折，代表是普通8折
        * flag3 = 0代表是周末全价
        * */
 
        double[] sum = new double[10];//算单桌打折后总价
        double[] beforesum = new double[10];//算单桌打折前总价
 
        double[] spicy = new double[20];//辣口味度计算
        double[] acidity = new double[20];//酸口味度计算
        double[] sweetness = new double[20];//甜口味度计算
 
        String[] show_spicy = {"不辣","微辣","稍辣","辣","很辣","爆辣"};
        String[] show_acidity = {"不酸","微酸","稍酸","酸","很酸"};
        String[] show_sweetness = {"不甜","微甜","稍甜","甜"};
 
        int[] fenshu_spicy = new int[10];//计算辣菜的份数
        int[] fenshu_acidity = new int[10];//计算酸菜的份数
        int[] fenshu_sweetness = new int[10];//计算甜菜的份数
 
        String[] name = new String[10];//记录客户名字
        String[] telephone = new String[10];//记录客户电话
 
        int k = 0;//桌子数
 
        while (true) {
            String str = sc.nextLine();
            count = str.split(" ");
            flag = count.length;
            if (count[0].equals("end") && flag == 1) {
                end = 1;
            }
            if (count[0].equals("table") && flag == 7) {
                if (j > 0) {
                        k++;
                        //计算最终的口味度，除以总份数
                }
                j++;
                sum[j-1] = 0;
                order[j-1] = new Order();
                number[j-1] = 0;
 
            }  //用来判断是不是订单和菜单混合的标记点
            if (j > 0) {
//                if (flag == 2) {   //删除菜品记录
//                    if (count[1].equals("delete")) {
//                        order[j-1].delARecordByOrderNum(Integer.parseInt(count[0]));
//                    } else {
//                        System.out.println("invalid dish");
//
//                    }
//                }
 
                if (flag == 7) {  //桌子信息的输入
                    if (count[0].equals("table")) {
                        int len = count[3].length();//计算客户姓名的长度
                        int len1 = count[4].length();//计算客户电话的长度
                        int b = 0;//是否桌子信息正确
 
                        if (count[1].charAt(0) == '0' || !(count[1].charAt(0) >= '1'
                                && count[1].charAt(0) <= '5')) {
                            System.out.println("wrong format");
                            b = 1;
                        } //桌号正常
 
                        if (len > 10) { //客户姓名不能超过10位
                            System.out.println("wrong format");
                            b = 1;
                        }
 
                        if (len1 != 11) {  //客户电话不能超过11位
                            boolean tel;
                            tel = count[4].matches("(181|180|189|133|135|136)\\d{8}");
                            if (!tel) {
                                System.out.println("wrong format");
                                b = 1;
                            }
                        }
                        if(b == 1){
                            return;
                        }
 
                        name[j - 1] = count[3];
                        telephone[j - 1] = count[4];
 
                        table_num[j-1] = Integer.parseInt(count[1]);
 
                        String[] arr = count[5].split("/");//将年分割开来
                        String[] arr1 = count[6].split("/");//将时间分割开来
                        int year = Integer.parseInt(arr[0]);
                        int month = Integer.parseInt(arr[1]);
                        int day = Integer.parseInt(arr[2]);//将日期分开
 
                        int hh = Integer.parseInt(arr1[0]);
                        int mm = Integer.parseInt(arr1[1]);
                        int ss = Integer.parseInt(arr1[2]);//将时间分开
 
                        if (arr1[1].length() > 2 || arr1[2].length() > 2) {
                            System.out.println("wrong format");
                            return;
                        }
                        int c = 0;//判断营业时间正确的标记点
                        if (month > 12 || day > 31 || year < 1000 || year > 9999) {
                            c = 2;
                        } else {
                            if (year < 2022 || year > 2023) {
                                c = 3;
                            } else {
                                Calendar cal = Calendar.getInstance();
                                cal.set(year, month - 1, day - 1);
 
                                if ((cal.get(Calendar.DAY_OF_WEEK) == 7)
                                        || (cal.get(Calendar.DAY_OF_WEEK) == 6)) {
                                    if ((hh >= 10 && hh <= 20) || (hh == 9 && mm >= 30) || (hh == 21 && mm <= 29)
                                            || (hh == 21 && mm == 30 && ss == 0)) {
                                        c = 1;
                                        flag3 = 0;
                                    } //周末全价时间判断
                                } else {
                                    if (hh >= 17 && hh <= 19) {
                                        flag3 = 2;
                                        c = 1;
                                    }
                                    if (hh == 20 && mm <= 29) {
                                        flag3 = 2;
                                        c = 1;
                                    }
                                    if (hh == 20 && mm == 30 && ss == 0) {
                                        flag3 = 2;
                                        c = 1;
                                    }
                                    if ((hh >= 11 && hh <= 13) || (hh == 10 && mm >= 30) ||
                                            (hh == 14 && mm <= 29)
                                            || (hh == 14 && mm == 30 && ss == 0)) {
                                        flag3 = 1;
                                        c = 1;
                                    }
                                }
                                if (c == 0) {
                                    System.out.println("table " + table_num[j - 1] + " out of opening hours");
                                    return;
                                }
                                System.out.println("table " + table_num[j - 1] + ": ");//输出桌号信息
                            }
                        }  //符合时间范围
                        if (c == 2) {
                            System.out.println(Integer.parseInt(count[1]) + " date error");
                        }
                        if (c == 3) {
                            System.out.println("not a valid time period");
                        }
                    }
                }
 
                if (flag == 4 || flag == 5 || flag == 6) {  //点菜的记录
                        if (flag == 4) {
                            for (int i = 0; i < flag1; i++) {
                                if (count[1].equals(menu.dishs[i].name)) {
                                    flag2 = 1;
                                    break;
                                }
                            }  //判断这个菜是否再菜单中有
                            if (flag2 == 1) {   //当存在
                                order[j - 1].addARecord(Integer.parseInt(count[0]), count[1],
                                        Integer.parseInt(count[2]), Integer.parseInt(count[3]), menu);
 
                                System.out.println(Integer.parseInt(count[0]) + " " +
                                        count[1] + " " + order[j - 1].records[number[j - 1]].getPrice());
                                //输出单笔
 
 
                                if (flag3 == 1) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.6 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 0) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 2) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.8 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                number[j - 1]++;
                                beforesum[j - 1] = order[j - 1].getTotalPrice();
                            }
                        }//点普通菜的记录
                        if(flag == 5) {  //当点特色菜的的时候
                            int suitable_s = 1;//判断辣口味度是否合适
                            int suitable_a = 1;//判断酸口味度是否合适
                            int suitable_w = 1;//判断甜口味度是否合适
 
                            for (int i = 0; i < flag1; i++) {
                                if (count[1].equals(menu.dishs[i].name)) {
                                    flag2 = 1;
                                    break;
                                }
                            }
                            for (String s : list) {//从辣中判断
                                if (count[1].equals(s)) {
                                    if ((Integer.parseInt(count[2]) < 0) || (Integer.parseInt(count[2]) > 5)) {
                                        System.out.println("spicy num out of range :" + Integer.parseInt(count[2]));
                                        suitable_s = 0;
                                    }
                                    else {
                                        fenshu_spicy[j - 1] += Integer.parseInt(count[4]);
                                        //list_s[number[j - 1]] = Integer.parseInt(count[2]);
                                        spicy[k] += (Integer.parseInt(count[2]) *  Integer.parseInt(count[4]));
                                    }//记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                }
 
                            }//判断这个菜是否再菜单中有
 
                            for (String s : list1) {//从酸中判断
                                if (count[1].equals(s)) {
                                    if ((Integer.parseInt(count[2]) < 0) || (Integer.parseInt(count[2]) > 4)) {
                                        System.out.println("acidity num out of range :" + Integer.parseInt(count[2]));
                                        suitable_a = 0;
                                    }else {
                                        fenshu_acidity[j - 1] += Integer.parseInt(count[4]);
                                        //list_a[number[j - 1]] = Integer.parseInt(count[2]);
                                        acidity[k] += (Integer.parseInt(count[2]) *  Integer.parseInt(count[4]));
                                    }
                                    //记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                }
 
                            }//判断这个菜是否再菜单中有
 
                            for (String s : list2) {//从甜中判断
                                if (count[1].equals(s)) {
                                    if ((Integer.parseInt(count[2]) < 0) || (Integer.parseInt(count[2]) > 3)) {
                                        System.out.println("sweetness num out of range :" + Integer.parseInt(count[2]));
                                        suitable_w = 0;
                                    }
                                    else {
                                        fenshu_sweetness[j - 1] += Integer.parseInt(count[4]);
                                        //list_w[number[j - 1]] = Integer.parseInt(count[2]);
                                        sweetness[k] += (Integer.parseInt(count[2]) *  Integer.parseInt(count[4]));
                                    //记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                    }
                                }
 
                            }//判断这个菜是否再菜单中有
 
                            if (flag2 == 1 && suitable_a == 1 && suitable_s == 1 && suitable_w == 1) {   //当存在
                                order[j - 1].addARecord(Integer.parseInt(count[0]), count[1],
                                        Integer.parseInt(count[3]), Integer.parseInt(count[4]), menu);
 
                                System.out.println(Integer.parseInt(count[0]) + " " +
                                        count[1] + " " + order[j - 1].records[number[j - 1]].getPrice());
                                //输出单笔
 
                                if (flag3 == 1) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.7 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 0) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 2) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.7 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                number[j - 1]++;
                                beforesum[j - 1] = order[j - 1].getTotalPrice();
                            }
                        }
                        if(flag == 6){
                            int suitable_s = 1;//判断辣口味度是否合适
                            int suitable_a = 1;//判断酸口味度是否合适
                            int suitable_w = 1;//判断甜口味度是否合适
 
                            for (int i = 0; i < flag1; i++) {
                                if (count[2].equals(menu.dishs[i].name)) {
                                    flag2 = 1;
                                    break;
                                }
                            }
                            for (String s : list) {//从辣中判断
                                if (count[2].equals(s)) {
                                    if ((Integer.parseInt(count[3]) < 0) || (Integer.parseInt(count[3]) > 5)) {
                                        System.out.println("spicy num out of range :" + Integer.parseInt(count[3]));
                                        suitable_s = 0;
                                    }
                                    else {
                                        fenshu_spicy[Integer.parseInt(count[0]) - 1] += Integer.parseInt(count[5]);
                                        //list_s[number[j - 1]] = Integer.parseInt(count[2]);
                                        spicy[Integer.parseInt(count[0]) - 1] += (Integer.parseInt(count[3]) *  Integer.parseInt(count[5]));
                                    }//记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                }
 
                            }//判断这个菜是否再菜单中有
 
                            for (String s : list1) {//从酸中判断
                                if (count[2].equals(s)) {
                                    if ((Integer.parseInt(count[3]) < 0) || (Integer.parseInt(count[3]) > 4)) {
                                        System.out.println("acidity num out of range :" + Integer.parseInt(count[3]));
                                        suitable_a = 0;
                                    }else {
                                        fenshu_acidity[Integer.parseInt(count[0]) - 1] += Integer.parseInt(count[5]);
                                        //list_a[number[j - 1]] = Integer.parseInt(count[2]);
                                        acidity[Integer.parseInt(count[0]) - 1] += (Integer.parseInt(count[3]) *  Integer.parseInt(count[5]));
                                    }
                                    //记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                }
                            }//判断这个菜是否再菜单中有
 
                            for (String s : list2) {//从甜中判断
                                if (count[2].equals(s)) {
                                    if ((Integer.parseInt(count[3]) < 0) || (Integer.parseInt(count[3]) > 3)) {
                                        System.out.println("sweetness num out of range :" + Integer.parseInt(count[3]));
                                        suitable_w = 0;
                                    }
                                    else {
                                        fenshu_sweetness[Integer.parseInt(count[0]) - 1] += Integer.parseInt(count[5]);
                                        //list_w[number[j - 1]] = Integer.parseInt(count[2]);
                                        sweetness[Integer.parseInt(count[0]) - 1] += (Integer.parseInt(count[3]) *  Integer.parseInt(count[5]));
                                        //记录对应菜系的口味度，放在不同的数组里，以用来计算最终口味度
                                    }
                                }
 
                            }//判断这个菜是否再菜单中有
                            if (flag2 == 1 && suitable_a == 1 && suitable_s == 1 && suitable_w == 1) {   //当存在
                                order[j - 1].addARecord(Integer.parseInt(count[1]), count[2],
                                        Integer.parseInt(count[4]), Integer.parseInt(count[5]), menu);
 
                                System.out.println(Integer.parseInt(count[1]) + " " +
                                        "table" + " " + j + " pay for table " + Integer.parseInt(count[0]) +  " " + order[j - 1].records[number[j - 1]].getPrice());
                                //输出单笔
 
                                if (flag3 == 1) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.7 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 0) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + order[j - 1].records[number[j - 1]].getPrice();
                                }
                                if (flag3 == 2) {
                                    sum[j - 1] = Math.round(sum[j - 1]) + 0.7 * order[j - 1].records[number[j - 1]].getPrice();
                                }
                                number[j - 1]++;
                                beforesum[j - 1] = order[j - 1].getTotalPrice();
                            }
                        }
 
                        if (flag2 == 0) {  //当菜名不存在时
                            System.out.println(count[1] + " does not exist");
                        }
                        flag2 = 0;
                }
                int delete = -1;
                if(flag == 2 && count[1].equals("delete")) {//删除的记录
                    for (int i = 0; i < number[j - 1]; i++) {
                        if (Integer.parseInt(count[0]) == order[j - 1].records[i].orderNum) {
                            delete = 0;
                            beforesum[j - 1] -= order[j - 1].records[i].getPrice();
                            int real_s = 1;
                            int real_a = 1;
                            int real_w = 1;
                            for (String s : list) {//从辣中判断
                                if (count[1].equals(s)) {
                                    real_s = 0;
                                break;
                                }
                            }
                            for (String s : list1) {//从酸中判断
                                if (count[1].equals(s)){
                                    real_a = 0;
                                    break;
                                }
 
                            }
                            for (String s : list2) {//从甜中判断
                                if (count[1].equals(s)){
                                    real_w = 0;
                                    break;
                                }
                            }
                            if ( real_s == 1 && real_a == 1 && real_w == 1){
                                if (flag3 == 1) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - 0.6 * order[j - 1].records[i].getPrice();
                                }
                                if (flag3 == 0) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - order[j - 1].records[i].getPrice();
                                }
                                if (flag3 == 2) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - 0.8 * order[j - 1].records[i].getPrice();
                                }
                            }else {
                                if (flag3 == 1) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - 0.7 * order[j - 1].records[i].getPrice();
                                }
                                if (flag3 == 0) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - order[j - 1].records[i].getPrice();
                                }
                                if (flag3 == 2) {
                                    sum[j - 1] = Math.round(sum[j - 1]) - 0.7 * order[j - 1].records[i].getPrice();
                                }
                            }
                            break;
                        }
                    }
                    if(delete == -1) {
                        System.out.println("delete error");
                    }
                    delete = -1;
                }
 
 
            } else {  //菜品录入
                if (flag == 2) {
                    int f2 = 0;//用来判断是否菜品价格为整数
                    int len1 = count[1].length();
                    for (int i = 0; i < len1; i++) {
                        if (!Character.isDigit(count[1].charAt(i))) {
                            System.out.println("wrong format");
                            f2 = 1;
                            break;
                        }
                    }
                    if (f2 == 0) {
                        if (Integer.parseInt(count[1]) > 300 || Integer.parseInt(count[1]) < 0) {
                            System.out.println(count[0] + " price out of range " + Integer.parseInt(count[1]));
                        } else {
                            menu.addDish(count[0], Integer.parseInt(count[1]));
                            num[flag1] = 0;
                            //如果是普通菜就赋值0，代表
                            flag1++;
                        }
                    }
                }
 
                if(flag == 3){
                    System.out.println("wrong format");
                }
 
                if (flag == 4) {  //特价菜的菜单录入
                    if (count[3].equals("T")) {
                        menu.addDish(count[0], Integer.parseInt(count[2]));
                        if (count[1].equals("川菜")) {
                            list[flag1] = count[0];//如果是川菜就赋值，代表川菜
                            num[flag1] = 1;
                            flag1++;
                        }
                        if (count[1].equals("晋菜")) {
                            list1[flag1] = count[0];//如果是晋菜就赋值，代表晋菜
                            num[flag1] = 2;
                            flag1++;
                        }
                        if (count[1].equals("浙菜")) {
                            list2[flag1] = count[0];//如果是浙菜就赋值，代表浙菜
                            num[flag1] = 3;
                            flag1++;
                        }//记录不同菜系判断口味度需要
                    }
 
                }
 
            }
            if(end == 1){
                k++;
                break;
            }
        }
 
 
        //最终的输出
        for(int i = 0; i < k ; i++) { //依次输出每一桌
            spicy[i] = Math.round(spicy[i] / fenshu_spicy[i]);
            acidity[i] = Math.round(acidity[i] / fenshu_acidity[i]);
            sweetness[i] = Math.round(sweetness[i] / fenshu_sweetness[i]);
            //每个桌子结束后，计算口味度
 
            if(fenshu_spicy[i] != 0 && fenshu_acidity[i] == 0 && fenshu_sweetness[i] == 0) {//只有川菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 川菜 " + fenshu_spicy[i] + " " + show_spicy[(int) spicy[i]]);
            }
            if(fenshu_spicy[i] == 0 && fenshu_acidity[i] != 0 && fenshu_sweetness[i] == 0) {//只有晋菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 晋菜 " + fenshu_acidity[i] + " " + show_acidity[(int) acidity[i]]);
            }
            if(fenshu_spicy[i] == 0 && fenshu_acidity[i] == 0 && fenshu_sweetness[i] != 0) {//只有浙菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 浙菜 " + fenshu_sweetness[i] + " " + show_sweetness[(int) sweetness[i]]);
            }
            if(fenshu_spicy[i] != 0 && fenshu_acidity[i] != 0 && fenshu_sweetness[i] == 0) { //没有浙菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 川菜 " + fenshu_spicy[i] + " " + show_spicy[(int) spicy[i]]
                        + " 晋菜 " + fenshu_acidity[i] + " " + show_acidity[(int) acidity[i]]);
            }
            if(fenshu_spicy[i] != 0 && fenshu_acidity[i] == 0 && fenshu_sweetness[i] != 0) {//没有晋菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 川菜 " + fenshu_spicy[i] + " " + show_spicy[(int) spicy[i]]
                        + " 浙菜 " + fenshu_sweetness[i] + " " + show_sweetness[(int) sweetness[i]]);
            }
            if(fenshu_spicy[i] == 0 && fenshu_acidity[i] != 0 && fenshu_sweetness[i] != 0) {//没有川菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 晋菜 " + fenshu_acidity[i] + " " + show_acidity[(int) acidity[i]]
                        + " 浙菜 " + fenshu_sweetness[i] + " " + show_sweetness[(int) sweetness[i]]);
            }
            if(fenshu_spicy[i] != 0 && fenshu_acidity[i] != 0 && fenshu_sweetness[i] != 0) {//都有
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " 川菜 " + fenshu_spicy[i] + " " + show_spicy[(int) spicy[i]]
                        + " 晋菜 " + fenshu_acidity[i] + " " + show_acidity[(int) acidity[i]]
                        + " 浙菜 " + fenshu_sweetness[i] + " " + show_sweetness[(int) sweetness[i]]);
            }
            if(fenshu_spicy[i] == 0 && fenshu_acidity[i] == 0 && fenshu_sweetness[i] == 0) {//没有川菜
                System.out.println("table " + table_num[i] + ": " + Math.round(beforesum[i]) + " "
                        + Math.round(sum[i]) + " ");
            }
 
        }
 
        if(j == 1) {
            System.out.println(name[0] + " " + telephone[0] + " " + Math.round(sum[j - 1]));
        }
        else {
            for (int i = 1; i < j; i++) {
                if (name[i].equals(name[i - 1])) {
                    sum[i] += sum[i - 1];
                    sum[i - 1] = 0;
                }
            }
            int change_name = 0;
 
            String name1;//中介类
            String tele1;//中介类
            double sum1;//中介类
            for (int i = 1; i < j; i++) {
                if (!name[i].equals(name[i - 1])) {
                    int m;
                    int l1 = name[i].length();
                    int l2 = name[i - 1].length();
                    m = Math.min(l1, l2);
                    for (int n = 0; n < m; n++) {
                        if (name[i - 1].charAt(n) > name[i].charAt(n)) {
                            change_name = i;
                            break;
                        }
                    }
                    if(change_name == i) {
 
                        name1 = name[i - 1];
                         name[i - 1] = name[i];
                         name[i] = name1;
 
                        tele1 = telephone[i - 1];
                        telephone[i - 1] = telephone[i];
                        telephone[i] = tele1;
 
                        sum1 = sum[i - 1];
                        sum[i - 1] = sum[i];
                        sum[i] = sum1;
                    }
                    change_name = 0;
                }
            }
            for (int i = 0; i < j; i++) {
                if (sum[i] != 0) {
                    System.out.println(name[i] + " " + telephone[i] + " " + Math.round(sum[i]));
                }
            }
        }
    }
}

 

期中考试试题

7-1 测验1-圆类设计

创建一个圆形类（Circle），私有属性为圆的半径，从控制台输入圆的半径，输出圆的面积

输入格式:

输入圆的半径，取值范围为(0,+∞)，输入数据非法，则程序输出Wrong Format，注意：只考虑从控制台输入数值的情况

输出格式:

输出圆的面积（保留两位小数，可以使用String.format(“%.2f”,输出数值）控制精度）

我的类图：

 

我的代码：

 

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Circle circle = new Circle();
        double r = sc.nextDouble();
        double area;
        if (r > 0) {
            circle.setR(r);
            area = circle.setArea();
            System.out.println(String.format("%.2f", area));
        } else {
            System.out.println("Wrong Format");
        }
    }
}
 
class Circle {
    private double r;
 
    Circle() {
    }
 
    public double setArea() {
        double area = Math.PI * r * r;
        return area;
    }
 
 
    public double getR() {
        return r;
    }
 
    public void setR(double r) {
        this.r = r;
    }
}

我的分析：

错误处理：当前代码对半径的输入进行了基本的错误判断，如果半径小于等于0，则输出"Wrong Format"。然而，可能还需要进一步验证用户输入的类型是否正确，以防止出现异常或错误的输入。例如，可以使用try-catch块来捕获用户输入非数字的情况。输入验证：如果需要更复杂的输入验证，例如只允许输入数值范围在一定范围内的情况，可以在setR方法中添加验证逻辑，确保输入值满足特定条件。方法命名：在Circle类中，setArea方法的命名可能会引起困惑，因为它并没有设置任何值，而是计算并返回圆的面积。考虑将其命名为calculateArea或getArea，以更准确地反映其功能。注释和文档：在代码中，添加注释以解释类和方法的目的、参数和返回值的含义，以使代码更易读和理解。此外，可以添加文档来详细描述类和方法的使用方法和注意事项。

 

7-2 测验2-类结构设计

设计一个矩形类，其属性由矩形左上角坐标点（x1，y1）及右下角坐标点（x2，y2）组成，其中，坐标点属性包括该坐标点的X轴及Y轴的坐标值（实型数），求得该矩形的面积。类设计如下图：

 

 

输入格式:

分别输入两个坐标点的坐标值x1，y1，x2，y2。

输出格式:

输出该矩形的面积值（保留两位小数）。

 

我的类图：

 

 

 我的代码:

 

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Rectangle rectangle = new Rectangle();
        double x1, x2, y1, y2;
        x1 = sc.nextDouble();
        rectangle.setX(x1);
        y1 = sc.nextDouble();
        rectangle.setY(y1);
        x2 = sc.nextDouble();
        rectangle.setX(x2);
        y2 = sc.nextDouble();
        rectangle.setY(y2);
        double length = rectangle.getLength(x1, x2);
        double height = rectangle.getHeight(y1, y2);
        double area = rectangle.getArea();
        System.out.println(String.format("%.2f",area));
 
    }
}
 
class Rectangle extends Point {
    private Point topLeftPoint;
    private Point lowerRightPoint;
    private double length;
    private double height;
    private double area;
 
    public Rectangle() {
    }
 
    public Rectangle(Point topLeftPoint, Point lowerRightPoint) {
        this.topLeftPoint = topLeftPoint;
        this.lowerRightPoint = lowerRightPoint;
    }
 
    public Point getTopLeftPoint() {
        return topLeftPoint;
    }
 
    public void setTopLeftPoint(Point topLeftPoint) {
        this.topLeftPoint = topLeftPoint;
    }
 
    public Point getLowerRightPoint() {
        return lowerRightPoint;
    }
 
    public void setLowerRightPoint(Point lowerRightPoint) {
        this.lowerRightPoint = lowerRightPoint;
    }
 
    public double getLength(double x1, double x2) {
        length = x1 - x2;
        return (length < 0) ? -length : length;
    }
 
    public double getHeight(double y1, double y2) {
        height = y1 - y2;
        return (height < 0) ? -height : height;
    }
 
    public double getArea() {
        area = length * height;
        return (area < 0) ? -area : area;
    }
}
 
class Point {
    public double x;
    public double y;
 
    public Point() {
    }
 
    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
    public double getX() {
        return x;
    }
 
    public void setX(double x) {
        this.x = x;
    }
 
    public double getY() {
        return y;
    }
 
    public void setY(double y) {
        this.y = y;
    }
}

 

我的分析：

这题代码我并没有用题目建议的类来写，但最后答案确实是对的，我省去了一些麻烦的步骤，用的是较简单的方法，但是代码中也会存在很多问题。代码中对输入的坐标值没有进行有效性验证。在输入坐标值之后，可以对其进行验证，以确保输入值的合法性。在Rectangle类中，计算矩形长度和高度的方法（getLength和getHeight）使用了绝对值函数来确保结果为正数。这样的设计可以避免负数结果的出现。 在Rectangle类中，length、height和area等变量没有使用private修饰，并且可以直接访问。建议将这些变量设置为私有，并通过对应的getter和setter方法进行操作，以封装数据并提供更好的控制。 在Point类中，提供了两个构造方法，但在Rectangle类的默认构造方法中没有使用这些构造方法。建议在默认构造方法中使用提供的构造方法来创建topLeftPoint和lowerRightPoint对象。代码中没有定义toString方法来提供对象的字符串表示。建议在Point和Rectangle类中实现toString方法，方便调试和打印对象信息。

 

7-3 测验3-继承与多态

将测验1与测验2的类设计进行合并设计，抽象出Shape父类（抽象类），Circle及Rectangle作为子类，类图如下所示：

 

试编程完成如上类图设计，主方法源码如下（可直接拷贝使用）：

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        
        int choice = input.nextInt();
        
        switch(choice) {
        case 1://Circle
            double radiums = input.nextDouble();
            Shape circle = new Circle(radiums);
            printArea(circle);
            break;
        case 2://Rectangle
            double x1 = input.nextDouble();
            double y1 = input.nextDouble();
            double x2 = input.nextDouble();
            double y2 = input.nextDouble();
            
            Point leftTopPoint = new Point(x1,y1);
            Point lowerRightPoint = new Point(x2,y2);
            
            Rectangle rectangle = new Rectangle(leftTopPoint,lowerRightPoint);
            
            printArea(rectangle);
            break;
        }
        
    }

 

其中，printArea(Shape shape)方法为定义在Main类中的静态方法，体现程序设计的多态性。

输入格式:

输入类型选择（1或2，不考虑无效输入）
对应图形的参数（圆或矩形）

输出格式:

图形的面积（保留两位小数）

 

我的类图：

 

 我的代码：

 

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner sc = new Scanner(System.in);
 
        int choice = sc.nextInt();
 
        switch(choice) {
            case 1://Circle
                double radium = sc.nextDouble();
                Shape circle = new Circle(radium);
                if(radium>0) {
                    double area1 = circle.getArea();
                    System.out.println(String.format("%.2f", area1));
                }
                else{
                    System.out.println("Wrong Format");
                }
                break;
            case 2://Rectangle
                double x1 = sc.nextDouble();
                double y1 = sc.nextDouble();
                double x2 = sc.nextDouble();
                double y2 = sc.nextDouble();
 
                Point leftTopPoint = new Point(x1,y1);
                Point lowerRightPoint = new Point(x2,y2);
 
                Rectangle rectangle = new Rectangle(leftTopPoint, lowerRightPoint) {
 
                };
 
                double length = rectangle.getLength(x1, x2);
                double height = rectangle.getHeight(y1, y2);
                double area2=rectangle.getArea();
                System.out.println(String.format("%.2f",area2));
                break;
 
 
 
        }
    }
 
}
 
 
abstract class Shape{
    public double area;
    abstract void Shape();
    double getArea(){
        return area;
    }
}
 
abstract class Rectangle extends Shape {
    private Point topLeftPoint;
    private Point lowerRightPoint;
    private double length;
    private double height;
    private double area;
    void Shape(){
 
    }
 
    public Rectangle() {
    }
 
    public Rectangle(Point topLeftPoint, Point lowerRightPoint) {
        this.topLeftPoint = topLeftPoint;
        this.lowerRightPoint = lowerRightPoint;
    }
 
    public Point getTopLeftPoint() {
        return topLeftPoint;
    }
 
    public void setTopLeftPoint(Point topLeftPoint) {
        this.topLeftPoint = topLeftPoint;
    }
 
    public Point getLowerRightPoint() {
        return lowerRightPoint;
    }
 
    public void setLowerRightPoint(Point lowerRightPoint) {
        this.lowerRightPoint = lowerRightPoint;
    }
 
    public double getLength(double x1, double x2) {
        length = x1 - x2;
        return (length < 0) ? -length : length;
    }
 
    public double getHeight(double y1, double y2) {
        height = y1 - y2;
        return (height < 0) ? -height : height;
    }
 
    public double getArea() {
        area = length * height;
        return (area < 0) ? -area : area;
    }
}
 
class Circle extends Shape{
    private double radiums;
    void Shape(){
 
    }
 
    public Circle() {
    }
 
    public Circle(double radiums) {
        this.radiums = radiums;
    }
 
    public double getRadiums() {
        return radiums;
    }
 
    public void setRadiums(double radiums) {
        this.radiums = radiums;
    }
 
    public double getArea(){
        double area=3.141592657*radiums*radiums;
        return area;
    }
}
class Point {
    public double x;
    public double y;
 
    public Point() {
    }
 
    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
    public double getX() {
        return x;
    }
 
    public void setX(double x) {
        this.x = x;
    }
 
    public double getY() {
        return y;
    }
 
    public void setY(double y) {
        this.y = y;
    }
 
}

 

我的分析：

代码也存在一些问题：缺少错误处理，代码中没有对用户的输入进行验证和错误处理。用户可能会输入无效的数据，例如非数字字符或负数。应该添加输入验证逻辑，以确保输入的数据类型正确且合法。以及代码中缺少注释来解释类和方法的目的、参数和返回值的含义。建议通过注释来提供必要的解释，以提高代码的可读性和可维护性。

 

7-4 测验4-抽象类与接口

在测验3的题目基础上，重构类设计，实现列表内图形的排序功能（按照图形的面积进行排序）。
提示：题目中Shape类要实现Comparable接口。

其中，Main类源码如下（可直接拷贝使用）：

public class Main {
    public static void main(String\[\] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        ArrayList<Shape> list = new ArrayList<>();    
 
        int choice = input.nextInt();
 
        while(choice != 0) {
            switch(choice) {
            case 1://Circle
                double radiums = input.nextDouble();
                Shape circle = new Circle(radiums);
                list.add(circle);
                break;
            case 2://Rectangle
                double x1 = input.nextDouble();
                double y1 = input.nextDouble();
                double x2 = input.nextDouble();
                double y2 = input.nextDouble();            
                Point leftTopPoint = new Point(x1,y1);
                Point lowerRightPoint = new Point(x2,y2);
                Rectangle rectangle = new Rectangle(leftTopPoint,lowerRightPoint);
                list.add(rectangle);
                break;
            }
            choice = input.nextInt();
        }    
 
        list.sort(Comparator.naturalOrder());//正向排序
 
        for(int i = 0; i < list.size(); i++) {
            System.out.print(String.format("%.2f", list.get(i).getArea()) + " ");
        }    
    }    
}

输入格式:

输入图形类型（1:圆形；2：矩形；0：结束输入）

输入图形所需参数

输出格式:

按升序排序输出列表中各图形的面积（保留两位小数），各图形面积之间用空格分隔。

 

我的类图：

 

 

我的代码：

 

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        ArrayList<Shape> shapeList = new ArrayList<>();
 
        int choice = scanner.nextInt();
 
        while (choice != 0) {
            switch (choice) {
                case 1: // Circle
                    double radius = scanner.nextDouble();
                    Shape circle = new Circle(radius);
                    shapeList.add(circle);
                    break;
                case 2: // Rectangle
                    double x1 = scanner.nextDouble();
                    double y1 = scanner.nextDouble();
                    double x2 = scanner.nextDouble();
                    double y2 = scanner.nextDouble();
                    Point topLeftPoint = new Point(x1, y1);
                    Point lowerRightPoint = new Point(x2, y2);
                    Rectangle rectangle = new Rectangle(topLeftPoint, lowerRightPoint);
                    shapeList.add(rectangle);
                    break;
            }
            choice = scanner.nextInt();
        }
 
        shapeList.sort(Comparator.naturalOrder());
 
        for (Shape shape : shapeList) {
            System.out.print(String.format("%.2f", shape.getArea()) + " ");
        }
    }
}
 
abstract class Shape implements Comparable<Shape> {
    abstract double getArea();
 
    @Override
    public int compareTo(Shape other) {
        return Double.compare(this.getArea(), other.getArea());
    }
}
 
class Rectangle extends Shape {
    private Point topLeftPoint;
    private Point lowerRightPoint;
 
    public Rectangle(Point topLeftPoint, Point lowerRightPoint) {
        this.topLeftPoint = topLeftPoint;
        this.lowerRightPoint = lowerRightPoint;
    }
 
    public double getLength() {
        double length = topLeftPoint.getX() - lowerRightPoint.getX();
        return (length < 0) ? -length : length;
    }
 
    public double getHeight() {
        double height = topLeftPoint.getY() - lowerRightPoint.getY();
        return (height < 0) ? -height : height;
    }
 
    public double getArea() {
        double area = getLength() * getHeight();
        return (area < 0) ? -area : area;
    }
}
 
class Circle extends Shape {
    private double radius;
 
    public Circle(double radius) {
        this.radius = radius;
    }
 
    public double getRadius() {
        return radius;
    }
 
    public double getArea() {
        double area = Math.PI * radius * radius;
        return area;
    }
}
 
class Point {
    private double x;
    private double y;
 
    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
    public double getX() {
        return x;
    }
 
    public double getY() {
        return y;
    }
}

三.遇到的困难和改进建议

困难：对Time类的懵懂、对抛出异常使用的懵懂、对String中nextLine的懵懂

改进建议：希望老师能给出答案

四.总结

经过这一阶段的学习，我对Java库中的诸多类和容器的使用有了进一步的了解，也认识到面向对象程序的设计思维非常重要，要合理地对多个类进行分离和封装，提高代码的可读性，使方法的调用与修改更加便捷，不影响到其他部分。

 

 

标签：count,题目,int,double,期中,Integer,parseInt,table,集及
From： https://www.cnblogs.com/jdrmy/p/17517738.html

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