Boolan Homework——Date类

问题描述

为Date类实现如下成员： 
1. 构造器，可以初始化年、月、日。 
2. 大于、小于、等于（> 、< 、==）操作符重载，进行日期比较。 
3. print() 打印出类似 2015-10-1 这样的格式。

然后创建两个全局函数： 
1. 第1个函数 CreatePoints生成10个随机的Date，并以数组形式返回 
2. 第2个函数 Sort 对第1个函数CreatePoints生成的结果，将其按照从小到大进行排序。

最后在main函数中调用CreatePoints，并调用print将结果打印出来。然后调用Sort函数对前面结果处理后，并再次调用print将结果打印出来。

代码实现

date.h头文件

#ifndef _DATE_
#define _DATE_

#include <iostream>
using namespace std;

class Date;

void Sort(Date* date, const int& n); 
void CreatePoints(Date* date, const int& n);
ostream& operator << (ostream& obj,const Date& date); 

class Date
{
    public:
        Date (int y = 0, int m = 0, int d = 0) : year(y), month(m), day(d) {} 

        bool operator == (const Date& date)
        {
            return year == date.year && month == date.month && day == date.day;
        }

        bool operator > (const Date& date)
        {
            if (year != date.year) return year > date.year;
            else if (month != date.month) return month > date.month;
            else if (day != date.day) return day > date.day;
            else return false;
        }

        bool operator < (const Date& date)
        {
            if (year != date.year) return year < date.year;
            else if (month != date.month) return month < date.month;
            else if (day != date.day) return day < date.day;
            else return false;
        }

        void Print()
        {
            cout << year << '-' << month << '-' << day << endl;
        }

    private:
        int year;
        int month;
        int day;

        friend void CreatePoints(Date* date, const int& n); 
        friend ostream& operator << (ostream& obj,const Date& date);   /*作业没要求，自己重载<<运算符 */ 
};

#endif

　　date.cpp实现文件

#include "date.h"
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

ostream& operator << (ostream& obj,const Date& date)
{
    return obj << date.year << '-' << date.month << '-' << date.day;
}

void CreatePoints(Date* date, const int& n)
{
    srand(time(NULL));   /*初始化种子*/
    /*没有考虑具体日期，如闰年、不同月份有不同天数等*/ 
    for (int i=0; i<n; ++i)
    {
        date[i].year = rand() % 2015 + 1;
        date[i].month = rand() % 12 + 1;
        date[i].day = rand() % 30 + 1;
    }
}

/*冒泡排序*/
void Sort(Date* date, const int& n)
{
    Date temp;
    for (int i=0; i<n; ++i)
    {
        for (int j=0; j<n-i-1; ++j)
        {
            if (date[j] > date[j+1])
            {
                temp = date[j];
                date[j] = date[j+1];
                date[j+1] = temp;
            }
        }
    }
}

　　main.cpp主程序

#include <iostream>
#include "date.h"
#define NUM 10 

using namespace std;

int main(int argc, char** argv) 
{   
    Date *date = new Date[NUM];
    CreatePoints(date,NUM); 
    cout << "before sort:" << endl;
    for (int i = 0; i < NUM; i++ )
    {
        date[i].Print();
        /*或cout << date[i] << endl;*/
    }

    Sort(date,NUM);
    cout << "after sort:" << endl;

    for (int i = 0; i < NUM; i++ )
    {
        date[i].Print();
        /*或cout << date[i] << endl;*/
    }   

    delete[] date;
    return 0;
}