C++程序设计(第2版)课后习题答案第13章

P317,13.3

#include <iostream>
#include <stdlib.h>
using namespace std;

static char daytable[2][13]={
    {0,31,28,31,30,31,30,31,31,30,31,30,31},
    {0,31,29,31,30,31,30,31,31,30,31,30,31}
};
class Date
{    
    //重载为友元
    //friend Date & operator+(Date &date,int d);
    friend ostream & operator<<(ostream &output,Date &d);
public:
    Date();
    Date(int y,int m,int d);
    ~Date();
    //重载为成员函数
    Date & operator+(int d);
    static int isLeap(int y);
    
protected:
    int year,month,day;
};

Date::Date()
{
    year=2013;
    month=3;
    day=25;
}

Date::Date(int y,int m,int d)
{
    year=y;
    month=m;
    day=d;
}

int Date::isLeap(int y)
{
    return (y%4==0 && y%100 || y%400==0);
}

Date::~Date()
{}

Date & Date::operator+(int d)
{
    while(day+d>daytable[isLeap(year)][month])
    {
        d-=daytable[isLeap(year)][month]-day;
        if(month==12)
        {
            year++;
            month=1;
        }
        else
            month++;
        day=0;
    }
    day+=d;
    
    return *this;
}


ostream & operator<<(ostream &output,Date &d)
{
    output<<d.year<<"-"<<d.month<<"-"<<d.day<<endl;
    return output;
}

/*
Date & operator+(Date &date,int d)
{
while(date.day+d>daytable[Date::isLeap(date.year)][date.month])
{
d-=daytable[Date::isLeap(date.year)][date.month]-date.day;
if(date.month==12)
{
date.year++;
date.month=1;
}
else
date.month++;
date.day=0;
}
date.day+=d;
return date;
}*/

void main()
{
    Date d(2013,3,25);
    d=d+365;
    cout<<d;
    //system("pause");
}

P317,13.7

#include <iostream>
#include <iomanip>
//#include <stdlib.h>
using namespace std;

class Time
{
    friend ostream & operator<<(ostream &output,Time &time);
    friend istream & operator>>(istream &input,Time &time);
public:
    Time(int h=0,int m=0,int s=0);
private:
    int hour,minute,second;
};

Time::Time(int h,int m,int s)
{
    hour=(h>=0 && h<=23)?h:0;
    minute=(m>=0 && m<=59)?m:0;
    second=(s>=0 && s<=59)?s:0;
}

ostream & operator<<(ostream &output,Time &time)
{
    output<<setw(2)<<setfill('0')<<time.hour<<":"
        <<setw(2)<<setfill('0')<<time.minute<<":"
        <<setw(2)<<setfill('0')<<time.second<<endl;
    //output<<time.hour<<":"<<time.minute<<":"<<time.second;
    return output;
}

istream & operator>>(istream &input,Time &time)
{
    char buffer[81];
    input.getline(buffer,3,'-');
    time.hour=atoi(buffer);
    input.getline(buffer,3,'-');
    time.minute=atoi(buffer);
    input.getline(buffer,3,'\n');
    time.second=atoi(buffer);
    return input;
}

void main(void)
{
    Time time(12,36,25);
    cout<<"hh-mm-ss:"<<endl;
    cin>>time;
    cout<<time;
    //system("pause");
}