C++作业3

来源：互联网发布：2017年网络销售好做吗编辑：程序博客网时间：2024/06/05 03:19

一、静态成员应用

#include <iostream>using namespace std;class Time{public:    Time(int=0,int=0,int=0);    void show_time( ); //根据is_24和from0，输出适合形式-20:23:5/8:23:5 pm/08:23:05 pm    void add_seconds(int); //增加n秒钟    void add_minutes(int); //增加n分钟    void add_hours(int); //增加n小时    static void change24();  //改变静态成员is_24，在12和24时制之间转换    static void changefrom0();   //改变静态成员from0，切换是否前导0 private:    static bool is_24; //为true时，24小时制，如20:23:5；为flase，12小时制，显示为8:23:5 pm    static bool from0; //为true时，前导0，8:23:5显示为08:23:05    int hour;    int minute;    int sec;};Time::Time(int h,int m,int s):hour(h),minute(m),sec(s){}void Time::add_seconds(int n){    sec=sec+n;    if(sec>59)    {        minute=minute+sec/60;        sec=sec%60;        if(minute>59)        {            hour=hour+minute/60;            minute=minute%60;        }    }}void Time::add_minutes(int n){    minute=minute+n;    if(minute>=60)    {        hour=hour+minute/60;        minute=minute%60;    }}void Time::add_hours(int n){    hour=(hour+n)%24;}bool Time::is_24=true;bool Time::from0=false;void Time::show_time(){     if(is_24)    {        if(from0)        {            cout<<(hour<10?"0":" ")<<hour<<":"<<(minute<10?"0":" ")<<minute<<":"<<(sec<10?"0":" ")<<sec<<endl;        }        else        {            cout<<hour<<":"<<minute<<":"<<sec<<endl;        }    }    else    {        if(from0)        {            cout<<(hour<10||(hour-12>=0&&hour-12<10)?"0":"")<<(hour>12?hour-12:hour)<<":"<<(minute<10?"0":"")<<minute<<":"<<(sec<10?"0":"")<<sec<<" "<<(hour>11?"pm":"am")<<endl;        }        else        {            cout<<(hour>12?hour-12:hour)<<":"<<minute<<":"<<sec<<" "<<(hour>11?"pm":"am")<<endl;        }    }}void Time::change24(){    is_24=!is_24;}void Time::changefrom0(){    from0=!from0;}int main( ){    Time t1(23,14,25),t2(8,45,6);    cout<<"24时制，不前导："<<endl;    cout<<"t1是："<<endl;    t1.show_time();    cout<<"t2是："<<endl;    t2.show_time();    t1.add_hours(10);    t2.add_hours(10);    Time::changefrom0();    cout<<"10小时后，切换是否前导："<<endl;    cout<<"t1是："<<endl;    t1.show_time();    cout<<"t2是："<<endl;    t2.show_time();    Time::change24();    cout<<"换一种制式："<<endl;    cout<<"t1是："<<endl;    t1.show_time();    cout<<"t2是："<<endl;    t2.show_time();    return 0;}

二、友元类

#include <iostream>using namespace std;class Date; //对Date类的提前引用声明class Time{public:    Time(int,int,int);    void add_a_second(Date &);  //增加1秒，1秒后可能会到了下一天，乃到下一月、下一年    void display(Date &);  //显示时间，格式：月/日/年 时:分:秒private:    int hour;    int minute;    int sec;};class Date{public:    Date(int,int,int);    friend class Time; //Time为Date的友元类private:    int month;    int day;    int year;};Date::Date(int m,int d,int y):year(y),day(d),month(m){}Time::Time(int h,int m,int s):hour(h),minute(m),sec(s){}void Time::add_a_second(Date &d){    sec=sec+1;    if(sec==60)    {        minute=minute+1;        sec=0;        if(minute==60)        {            hour=hour+1;            minute=0;            if(hour>=24)            {                d.day=d.day+1;                hour=0;                if(d.day==29)                {                    while(d.month==2)                    {                        d.month=d.month+1;                    }                    d.day=1;                }                if(d.day==31)                {                    while(d.month==4||d.month==6||d.month==9||d.month==11)                    {                        d.month=d.month+1;                    }                    d.day=1;                }                if(d.day==32)                {                    while(d.month==1||d.month==3||d.month==5||d.month==7||d.month==8||d.month==10||d.month==12)                    {                        d.month=d.month+1;                    }                    d.day=1;                    if(d.month==13)                    {                        d.year=d.year+1;                        d.month=1;                    }                }            }        }    }}void Time::display(Date &d){    cout<<d.year<<"/"<<d.month<<"/"<<d.day<<" "<<hour<<":"<<minute<<":"<<sec<<endl;}int main( ){    Time t1(23,59,32);    Date d1(12,31,2013);   //测试时，再试试Date d1(2,28,2013)会如何    for(int i=0; i<=100; i++)    {        t1.add_a_second(d1);        t1.display(d1);    }    return 0;}//下面定义两个类中的成员函数，要求不得再增加成员函数//注意体会在Time的成员函数中可以调用Date类的私有数据成员

0 0