1.前言
不知不觉一个月又过去了，也再次完成了三次pta上面的作业，总的来说，这几次pta实验在题量上比之前少了很多，但相对的，难度有了很多提升，其中第六次实验我更是连及格分都没有拿到。接下来我会对这几次实验进行分析，这几次实验涵盖了正则表达式、封装性。还有菜单和日期类程序，总的来说比上次复杂了不少，也更应该好好总结。废话不多说，接下来就开始总结分析一下这几次的代码
2.设计与分析
在这一块我会重点针对题目的源码进行分析，同时也会附上power designer所做的类图用以方便理解。首先要分析的是题目集四的7-1
这个题目是后面那个菜单程序的简单版，但是对于初见的我来说仍然是一道难题，等会放在后面和最后一道题一起讲
然后是题目集5的7-5
首先肯定是根据他给的设计类图给出年月日的定义，这里就只给出年的定义了，另外两个和这个相仿，就不赘述了。
class Year{
private int value;
public Year(){}
public Year(int value){
this.value=value;
}
public int getValue(){
return value;
}
public void setValue(int value){
this.value=value;
}
public boolean isLeapYear(){//判断是否为闰年
if((value%4==0&&value%100!=0)||value%400==0)
return true;
else
return false;
}
public boolean validate(){//校验数据合法性
if(value<=2050&&value>=1900)
return true;
else
return false;
}
public void yearIncrement(){
value=value+1;
}
public void yearReduction(){
value=value-1;
}
}
在把这三个主要的类都定义好之后，就要针对题目来实现功能了。
在Dateutil类里一共要完成三个功能，也就是求上下n天以及测试两日期之间相差的天数
首先是求下n天
public DateUtil getNextNDays(int n){
for (int i = 0; i < n; i++) {
if(day.getMonth().getYear().isLeapYear())
day.mon_maxnum[2] = 29;
else
day.mon_maxnum[2] = 28;
day.dayIncrement();
if(day.getValue() == day.mon_maxnum[day.getMonth().getValue()]+1){//
day.resetMin();
day.getMonth().monthIncrement();
}
if(day.getMonth().getValue() == 13){//月份为13，月份进位
day.getMonth().getYear().yearIncrement();
day.getMonth().resetMin();
}
}
return new DateUtil(day.getMonth().getYear().getValue() , day.getMonth().getValue(),day.getValue());
}
求上n天和这个类似，就不给出代码了。
但是在求两日期相差的天数前，要先判断两个日期的大小，不然没办法进行比较。
public boolean compareDates(DateUtil date){//date即为输入的年月日
if(day.getMonth().getYear().getValue() > date.day.getMonth().getYear().getValue()){//年
return true;
}else if(day.getMonth().getYear().getValue() == date.day.getMonth().getYear().getValue() && day.getMonth().getValue() > date.day.getMonth().getValue()){//月
return true;
}else if(day.getMonth().getYear().getValue() == date.day.getMonth().getYear().getValue() && day.getMonth().getValue() == date.day.getMonth().getValue() && this.day.getValue() > date.day.getValue()){//日
return true;
}
return false;
}
当然，两日期相同的特殊情况也是要考虑的。
public boolean equalTwoDates(DateUtil date){
return day.getMonth().getYear().getValue() == date.day.getMonth().getYear().getValue() && day.getMonth().getValue() == date.day.getMonth().getValue() && day.getValue() == date.day.getValue();
}
接下来在主函数里面用if语句来写选择就行了
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int year = 0;
int month = 0;
int day = 0;
int a,b;
a = input.nextInt();//输入判断类型
year = input.nextInt();
month = input.nextInt();
day = input.nextInt();//输入年月日
DateUtil c = new DateUtil(year,month,day);
if(a==1){//求下n天
b = input.nextInt();//输入n
if(!c.checkInputValidity()||b<0){//数据不合法
System.out.println("Wrong Format");
System.exit(0);
}
else
System.out.println(c.getNextNDays(b).showDate());
}
else if(a==2) {
b = input.nextInt();//输入n
if (!c.checkInputValidity() || b < 0) {
System.out.println("Wrong Format");
System.exit(0);
}
else
System.out.println(c.getPreviousNDays(b).showDate());
}
else if(a==3){
int y1,m1,d1;
y1 = input.nextInt();
m1 = input.nextInt();
d1 = input.nextInt();//输入第二个年月日
DateUtil date = new DateUtil(y1,m1,d1);
if(!c.checkInputValidity()||!date.checkInputValidity()){//如果数据不合法
System.out.println("Wrong Format");
System.exit(0);
}
else
System.out.println(c.getDaysofDates(date));
}
else
System.out.println("Wrong Format");
}
}
同时在这里给出类图方便理解。
接着是下一题，7-6，这题是上一题的升级版，正好放在一起讲。
这题看似和上一题差不多（实际上确实差不多），但是其中类和类直接的关系与上一题不同了，在这一题中，Dateutil可以直接访问其他三个类的value，由于年月日的代码我上面已经给出，这里就不给了，直接上Dateutil的代码，便于对比其不同。
先是求上下n天的：
public DateUtil getNextNDays(int n){//求下n天
for(int i=0;i<n;i++){
if(year.isLeapYear())
mon_maxnum[2]=29;
else
mon_maxnum[2]=28;
day.dayIncrement();
if(day.getValue() == mon_maxnum[month.getValue()]+1){
day.setValue(1);
month.monthIncrement();
}
if(month.getValue() == 13){
year.yearIncrement();
month.setValue(1);
}
}
return new DateUtil(year.getValue(),month.getValue(),day.getValue());
}
public DateUtil getPreviousNDays(int n){
for(int i=0;i<n;i++){
if(year.isLeapYear())
mon_maxnum[2]=29;
else
mon_maxnum[2]=28;
day.dayReduction();
if(day.getValue() == 0){
month.monthReduction();
if(month.getValue() == 0){
year.yearReduction();
month.setValue(12);
}
day.setValue(mon_maxnum[month.getValue()]);
}
}
return new DateUtil(year.getValue(), month.getValue(), day.getValue());
}
然后是求两个日期之间相差天数的：
public int getDaysofDates(DateUtil date){
int res = 0;
if(this.compareDates(date)){
while(true){
if(date.year.isLeapYear())
date.mon_maxnum[2] = 29;
else
date.mon_maxnum[2] = 28;
date.day.dayIncrement();
if(date.day.getValue() == date.mon_maxnum[date.month.getValue()] + 1){
date.month.monthIncrement();
date.day.setValue(1);
}
if(date.month.getValue() == 13){
date.year.yearIncrement();
date.month.resetMin();
}
if(date.year.getValue() == year.getValue() && date.month.getValue() == month.getValue() && date.day.getValue() == day.getValue()){
break;
}
res++;
}
}else{
while(true){
if(year.isLeapYear())
mon_maxnum[2] = 29;
else
mon_maxnum[2] = 28;
day.dayIncrement();
if(day.getValue() == mon_maxnum[month.getValue()] + 1){
month.monthIncrement();
day.setValue(1);
}
if(month.getValue() == 13){
year.yearIncrement();
month.resetMin();
}
if(date.year.getValue() == year.getValue() && date.month.getValue() == month.getValue() && date.day.getValue() == day.getValue()){
break;
}
res++;
}
}
return res + 1;
}
}
后面主函数啥的都大差不差了，给出类图就结束吧。
然后就是重磅的实验六了
这道题我当时并没有做出来，后来在我朋友的辅导下才得以完善代码。
首先是定义dish类
这里我还没有碰到什么问题，和之前那个7-3差不多：
class Dish{//菜品类
private String name;//菜品名称
private int unit_price;//单价
private String isSpecial = "F";
public Dish(){//无参构造
}
public Dish(String name,int unit_price,String isSpecial) {
this.name = name;
this.unit_price = unit_price;
this.isSpecial = isSpecial;
}
public Dish(String name,int unit_price) {
this.name = name;
this.unit_price = unit_price;
}
public void setIsSpecial(String isSpecial) {
this.isSpecial = isSpecial;
}
public int getPrice(int portion){//计算份额
return (int)(unit_price * (1 + (float)(portion - 1) / 2) + 0.5);
}
public int getUnit_price() {
return unit_price;
}
public String getIsSpecial() {
return isSpecial;
}
public void setName(String name){
this.name = name;
}
public String getName(){
return this.name;
}
public int setUnit_price(int unit_price){
return this.unit_price = unit_price;
}
}
接着就是菜单类，这里我碰到了第一个问题，怎么查找菜品返回dish
public Dish searchDish(String dishName){//在menu中查找菜品，返回Dish
int len = 0;
for (int j = 0;dishes[j] != null;j ++){
len ++;
}
for (int j = 0;j < len;j++){
if (dishes[j].getName().equals(dishName)){
return dishes[j];
}
}
return null;
}
除此之外，保存和添加菜品也是一大难点，
public Dish addDish(String dishName, int unit_price){//添加菜品
if (unit_price > 0 && unit_price < 300) {
if (i == ) {
dishes[] = new Dish(dishName, unit_price);
i++;
return dishes[];
} else {
dishes[i] = new Dish(dishName, unit_price);
i++;
return dishes[i];
}
}
return null;
}
public Dish addSpecialDish(String dishName, int unit_price,String isSpecial){//添加菜品
if (unit_price > 0 && unit_price < 300) {
if (i == ) {
dishes[] = new Dish(dishName, unit_price, isSpecial);
i++;
return dishes[0];
} else {
dishes[i] = new Dish(dishName, unit_price, isSpecial);
i++;
return dishes[i];
}
}
return null;
}
相对的，Record类就没这么难了，但是要定义的东西比较多，这里直接给出代码：
class Record{
private int orderNum;//序号
private Dish d = new Dish();//菜品
private int portion;//份额
private int num;//份数
private int price;
private boolean isValidPortion = true;
private boolean isValidNum = true;
public Record(){//无参构造
}
public Record(int orderNum,Dish d,int portion,int num){
this.orderNum = orderNum;
this.d = d;
this.portion = portion;
this.num = num;
}
public void setD(Dish d){
this.d = d;
}
public int getPrice(){//价格
return d.getPrice(portion)*num;
}
public Dish getD(){
return this.d;
}
public int getOrderNum(){
return this.orderNum;
}
public void setOrderNum(int orderNum) {
this.orderNum = orderNum;
}
public int getPortion() {
return portion;
}
public void setPortion(int portion) {
this.portion = portion;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
public void setPrice(int price) {
this.price = price;
}
public void isValidity(){
if (this.portion >= 1 && this.portion <= 3){
this.isValidPortion = true;
}else{
this.isValidPortion = false;
}
if (this.num >= && this.num <= ){
this.isValidNum = true;
}else{
this.isValidNum = false;
}
}
}
接着是table类，也就是看在哪一桌，这里要判断输入的订单桌号信息是否有效，有效则将桌号记录下来，无效则纪录无效,以及要判断日期是否合法
class Table{
private OrderTime orderTime = new OrderTime();//点菜时间
private int tableNum;
private boolean isValidTable = true;
private boolean isValidNum = true;//桌号范围
private boolean isValidNumFormat = true;//桌号是否为数字
private boolean dateData = true;//日期的数据是否合法
private boolean isValidDateData = true;//日期是否在范围内
private boolean isValidDateFormat = true;//日期格式是否合法
public boolean isValidNumFormat() {
return isValidNumFormat;
}
public boolean isValidDateData() {
return isValidDateData;
}
public boolean isValidDateFormat() {
return isValidDateFormat;
}
public boolean isDateData() {
return dateData;
}
public OrderTime getOrderTime() {
return orderTime;
}
public void setOrderTime(OrderTime orderTime) {
this.orderTime = orderTime;
}
public Table(OrderTime orderTime) {
this.orderTime = orderTime;
}
public Table() {
}
public boolean isValidTable() {
return isValidTable;
}
public boolean isValidNum() {
return isValidNum;
}
public void isValidity(String str){
String[] splitedStr = str.split(" ");
String[] splitedDate = splitedStr[splitedStr.length - 2].split("/");
String[] splitedDay = splitedStr[splitedStr.length - 1].split("/");
if (Integer.parseInt(splitedDate[0]) >= 2022 && Integer.parseInt(splitedDate[0]) <= 2023){
isValidDateData = true;
}else{
isValidDateData = false;
}
if (splitedStr[0].equals("table")){
isValidTable = true;
}else{
isValidTable = false;
}
if (splitedDate[0].matches("\\d{4}") && splitedDate[1].matches("\\d{1,2}") && splitedDate[2].matches("\\d{1,2}") &&
splitedDay[0].matches("\\d{1,2}") && splitedDay[1].matches("\\d{1,2}") && splitedDay[2].matches("\\d{1,2}")){
isValidDateFormat = true;
}else{
isValidDateFormat = false;
}
if (splitedStr[splitedStr.length - 3].matches("[1-9]\\d+")){
isValidNumFormat = true;
if (splitedStr[splitedStr.length - 3].matches("[1-9]|[1-4]\\d|5[0-5]")){
isValidNum = true;
}else{
isValidNum = false;
}
tableNum = Integer.parseInt(splitedStr[splitedStr.length-3]);
if (Integer.parseInt(splitedDate[1]) > 0 && Integer.parseInt(splitedDate[1]) <= 12) {//判断输入的年月是否合法
Calendar calendar = Calendar.getInstance();
calendar.set(Integer.parseInt(splitedDate[0]), Integer.parseInt(splitedDate[1]), Integer.parseInt(splitedDate[2]));
if (Integer.parseInt(splitedDate[2]) > 0 && Integer.parseInt(splitedDate[2]) <= calendar.getActualMaximum(Calendar.DAY_OF_MONTH)) {
if (Integer.parseInt(splitedDay[0]) >= 0 && Integer.parseInt(splitedDay[0]) <= 23 && Integer.parseInt(splitedDay[1]) >= 0 &&
Integer.parseInt(splitedDay[1]) <= 59 &&Integer.parseInt(splitedDay[2]) >= 0 && Integer.parseInt(splitedDay[2]) <= 59) {
orderTime.setOrderTime(Integer.parseInt(splitedDate[0]), Integer.parseInt(splitedDate[1]), Integer.parseInt(splitedDate[2])
, Integer.parseInt(splitedDay[0]), Integer.parseInt(splitedDay[1]), Integer.parseInt(splitedDay[2]));
}
}else{
dateData = false;
}
}else{
dateData = false;
}
}else{
isValidNumFormat = false;
}
}
public int getTableNum() {
return tableNum;
}
public void setTableNum(int tableNum) {
this.tableNum = tableNum;
}
}
最后就是时间日期这一块难点了，我将下面的代码批注了一下，这样更便于理解。
class WhichDay{//日期
private Order order = new Order();
private boolean isValidDate = true;
private int week = order.getTable().getOrderTime().getOrderTime().get(Calendar.DAY_OF_WEEK);
Calendar[] compareTime = new Calendar[];
public WhichDay() {
}
public Order getOrder() {
return order;
}
public void setOrder(Order order) {
this.order = order;
}
public void setCompareTime() {//记录营业时间
for (int i = ;i < ;i++){
compareTime[i] = Calendar.getInstance();
}
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
compareTime[].set(order.getTable().getOrderTime().getOrderTime().get(Calendar.YEAR),order.getTable().getOrderTime().getOrderTime().get(Calendar.MONTH)
,order.getTable().getOrderTime().getOrderTime().get(Calendar.DATE),,,);
}
public WhichDay(Order order) {
this.order = order;
}
public int getWeek() {
return week;
}
public void isValidDate(){//看是否为有效时间
if (week >= && week <= ){
if (((((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= compareTime[].getTimeInMillis())) &&
(order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[].getTimeInMillis())) ||
(((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= (compareTime[]).getTimeInMillis()) &&
((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[]).getTimeInMillis()))){
isValidDate = true;
}else if((((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= (compareTime[].getTimeInMillis())) &&
(order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[].getTimeInMillis())) ||
(((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= (compareTime[].getTimeInMillis())) &&
((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[].getTimeInMillis())))){
isValidDate = true;
}else{
isValidDate = false;
}
}else{
if ((((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= (compareTime[].getTimeInMillis())) &&
((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[].getTimeInMillis())))){
isValidDate = true;
}else if ((((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() >= (compareTime[].getTimeInMillis())) &&
((order.getTable().getOrderTime().getOrderTime()).getTimeInMillis() <= (compareTime[].getTimeInMillis())))){
isValidDate = true;
}else{
isValidDate = false;
}
}
}
public double setDiscount(){
double discount;
if (((order.getTable().getOrderTime().getOrderTime()).compareTo(compareTime[]) == 1) &&
(order.getTable().getOrderTime().getOrderTime()).compareTo(compareTime[]) == -1){
discount = .;
}else{
discount = .;
}
return discount;
}
public void setValidDate(boolean validDate) {
isValidDate = validDate;
}
public boolean getValidDate(){
return isValidDate;
}
}
最后再给出类图总结一下
3.踩坑心得
要说踩了的坑的话，那肯定还是不少的，比如7-1的时候曾经因为matches方法错过(没加^和&)
还有因为输出时用了printf导致输出超时
包括日期输出的时候没注意格式
这些都是现在踩的坑，也是吸取的经验。
4.改进建议
和之前一样，我有的时候还是改不掉printf的习惯，同时测试点较多的情况下，也会对自己错误的几个测试点怎么错的感到迷茫。另外，我发现有些题目如果改成正则表达式的形式会让代码不那么冗长，同时我的类与类之间的关系还是没有太清楚，也是要改进的点。
5.总结
最后，和之前一样做个总结，这几次作业可谓是让我初步体验到了Java的困难之处，甚至有一次pta作业没有做到及格，接下来不能怠惰了，要好好练习自己的代码水平，写出更好的代码。
标签：总结,return,int,getOrderTime,PTA,day,实验,getValue,public From： https://www.cnblogs.com/mlz1106/p/17365166.html