Day5：面试必考题目

日期类的实现(handwritten orOJ)

1.The content of the subject requirements

主要实现：

1.日期的加减

2.运算符重载

3.自定义拷贝构造、Full default copy construction

4.测试类

内容划分：

1.Date.h

2.Date.cpp

3.Test.cpp

2.Date class code implementation

//Date.h
#pragma once
#include<iostream>
using std::cin;
using std::cout;
using std::endl;

class Date
{
    
public:
	//判断平年
	bool isLeapYear(int year)
	{
    
		if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
			return true;
		else
			return false;
	}

	// 获取某年某月的天数
	int GetMonthDay(int year, int month) 
	{
    
		//assert(year>0 && month>0 && month<13);
		//Simple time notation
		static int Days[13] = {
     0,31,28,31,30,31,30,31,31,30,31,30,31 };
		if (year > 0 && month > 0 && month < 13)//ifYou can also use assertions to judge
		{
    
			if (month == 2 && isLeapYear(year))
				return 29;
			else
				return Days[month];
		}		
	}

	// 全缺省的构造函数---Constructors can only be written in a class
	Date(int year = 2022, int month = 1, int day = 1)
	{
    
		if (year > 0 &&
			month > 0 && month < 13 &&
			day>0 && day <= GetMonthDay(year, month))
		{
    
			_year = year;
			_month = month;
			_day = day;
		}
	}

	// 拷贝构造函数 d2(d1)
	Date(const Date& d) 
	{
    
		if (*this != d)
		{
    
			_year = d._year;
			_month = d._month;
			_day = d._day;
		}
	}

	// 赋值运算符重载---Self-generated writable or not,unless you customize it
    // d2 = d3 -> d2.operator=(&d2, d3)
	//Date& operator=(const Date& d) const;
	
	//析构函数 ~Date();---Self-generated writable or not

	// 日期+=天数
	Date& operator+=(int day);
	// 日期+天数
	Date operator+(int day);
	// 日期-天数
	Date operator-(int day);
	// 日期-=天数
	Date& operator-=(int day);
	// 前置++
	Date& operator++();
	// 后置++
	Date operator++(int);
	// 后置--
	Date operator--(int);
	// 前置--
	Date& operator--();

	// >运算符重载
	bool operator>(const Date& d);
	// ==运算符重载
	bool operator==(const Date& d);
	// >=运算符重载
	bool operator >= (const Date& d);
	// <运算符重载
	bool operator < (const Date& d);
	// <=运算符重载
	bool operator <= (const Date& d);
	// !=运算符重载
	bool operator != (const Date& d);

	// 日期-日期 返回天数
	int operator-(const Date& d);

	// 打印日期
	void Print()
	{
    
		cout << _year << "-" << _month << "-" << _day << endl;
	}

private:
	int _year;
	int _month;
	int _day;
};

//Date.cpp
#include"Date.h"

// 日期+=天数
Date& Date::operator+=(int day)
{
    
	if (day < 0)
		return *this -= -day;

	_day += day;
	while (_day > GetMonthDay(_year, _month))
	{
    
		_day -= GetMonthDay(_year, _month);
		_month++;
		if (_month == 13)
		{
    
			++_year;
			_month = 1;
		}
	}
	return *this;
}

// 日期+天数
Date Date::operator+(int day)
{
    
	Date ret(*this);
	ret += day;
	return ret;
}

// 日期-=天数
Date& Date::operator-=(int day)
{
    
	if (day < 0)
		return *this += -day;

	_day -= day;
	while (_day <= 0)
	{
    
		--_month;
		if (_month == 0)
		{
    
			_month = 12;
			--_year;
		}

		_day += GetMonthDay(_year, _month);
	}
	return *this;
}

// 日期-天数
Date Date::operator-(int day)
{
    
	Date ret(*this);
	ret -= day;
	return ret;
}

// 前置++
Date& Date::operator++()
{
    
	*this += 1;
	return *this;
}
// 后置++
Date Date::operator++(int)
{
    
	Date ret(*this);
	*this += 1;
	return ret;
}

// 后置--
Date Date::operator--(int)
{
    
	Date ret(*this);
	*this -= 1;
	return ret;
}
// 前置--
Date& Date::operator--()
{
    
	*this -= 1;
	return *this;
}

//Date addition and subtraction and pre- and post-summary：
//先写-=和+=Then interoperate to implement other operations
//Pre and post attention Post-add parameters,No parameters are added before,Use a backDate ret来中转*this


// >运算符重载(实现)
bool Date::operator>(const Date& d)
{
    
	if (_year > d._year ||
		_year==d._year &&_month > d._month ||
		_year>d._year && _month==d._month &&_day > d._day)
	{
    
		return true;
	}
	else
		return false;
}
// ==运算符重载(实现)
bool Date::operator==(const Date& d)
{
    
	return _year == d._year
		&& _month == d._month
		&& _day == d._day;
}
// >=运算符重载(互用)
bool Date::operator >= (const Date& d)
{
    
	return *this > d || *this == d;
}
// <运算符重载(互用)
bool Date::operator < (const Date& d)
{
    
	return !(*this>=d);
}
// <=运算符重载(互用)
bool Date::operator <= (const Date& d)
{
    
	//写成这个 return !(*this>d); Missing is equal to the situation
	return *this < d || *this == d;
}
// !=运算符重载(互用)
bool Date::operator != (const Date& d)
{
    
	return !(*this == d);
}

//运算符重载总结：
//实现两个,Other interoperability implementations,注意>= 和<=That equals judgment,Interoperable operator overloading is availableinline提高效率



// 日期-日期 返回天数
int Date::operator-(const Date& d)
{
    
	int flag = 1;
	Date max = *this;//represent large numbers
	Date min = d;//表示小数
	if (*this < d)//Automatic conversion of large and small numbers,保持max和min的正确
	{
    
		min = *this;
		max = d;
		flag = -1;
	}

	int n = 0;//n计数,一直让nAdd the decimal to the larger number to get the difference in days
	while (min != max)
	{
    
		++n;
		++min;
	}
	return n * flag;//×flagIt is to ensure the positive and negative of the number of days played
}

#include"Date.h"

void Test1()//测试运算符重载
{
    
	Date d1(2022, 1, 1);
	Date d2(2022, 2, 1);
	Date d3(2022, 2, 1);

	cout << "d1<d2：" << (d1 < d2) << endl;
	cout << "d1>d2：" << (d1 > d2) << endl;
	cout << "d1=d3：" << (d1 == d3) << endl;
	cout << "d2=d3：" << (d2 == d3) << endl;
	cout << "d1<=d3：" << (d1 <= d3) << endl;
	cout << "d1>=d2：" << (d1 >= d2) << endl;
	cout << endl;
}

void Test2()//Addition or subtraction of test days
{
    
	Date d1(2022, 1, 1);
	Date d2 = d1 + 15;
	cout << "d1的日期：";
	d1.Print();
	cout << "d2的日期(d1+15)：";
	d2.Print();
	cout << endl;
}

void Test3()//测试日期-日期=天数
{
    
	Date d1(2022, 1, 5);
	Date d2(2022, 2, 2);
	Date d3(2022, 5, 1);
	Date d4(2022, 3, 1);
	cout << "d1和d2的天数差：";
	cout << "d1-d2=" << (d1 - d2)<<endl;
	cout << "d3和d4的天数差：";
	cout << "d3-d4=" << (d3 - d4)<<endl;
	cout << endl;
}

void Test4()//测试 前置后置
{
    
	Date d1(2022, 1, 1);
	Date d2(2022, 1, 1);
	Date d3(2022, 1, 1);
	Date d4(2022, 1, 1);
	cout<<"d1++(2022,1,1):";
	cout << "原d1:";
	d1.Print();
	d1++;
	cout << "d1++后d1:";
	d1.Print();
	cout<<endl;

	cout << "d2--(2022,1,1):";
	cout << "原d2:";
	d2.Print();
	d2--;
	cout << "d2--后d2:";
	d1.Print();
	cout << endl;

	cout << "++d3(2022,1,1):";
	cout << "原d3:";
	++d3;
	d3.Print();
	cout << "++d3后d3:";
	d3.Print();
	cout << endl;

	cout << "--d4(2022,1,1):";
	cout << "原d4:";
	--d4;
	d4.Print();
	cout << "--d4后d4:";
	d4.Print();
	cout << endl;
}

int main()
{
    
	cout << "测试运算符重载："<<endl;
	Test1();
	Test2();
	Test3();
	Test4();
	return 0;
}

3.The date class code runs reasonably(Typesetting)