第六周项目4-静态成员应用

#include<iostream>
#include<cstdio>
using namespace std;

class time
{
public:
time(int=0,int=0,int=0);
void show_time();//根据is_24和from0，输出合适形式-20:23:5/8:23:5pm/08:23:05pm
void add_seconds(int x);//增加n秒钟
void add_minutes(int y);//增加n分钟
void add_hours(int z);//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false，12小时制，显示为8:23:5pm
static bool from0;//为true 时，前导0,8:23:5显示为08:23:05
int hour;
int minute;
int sec;
};
bool time::is_24=true;
bool time::from0=false;
time::time(int h,int m,int s)
{
hour=h;
minute=m;
sec=s;
}
void time::show_time()
{

if(from0)
{
if(hour<10)
cout<<"0"<<hour<<":";
else
cout<<hour<<":";
if(minute<10)
cout<<"0"<<minute<<":";
else
cout<<minute<<":";
if(sec<10)
cout<<"0"<<sec<<endl;
else
cout<<sec<<endl;
}

}
void time::add_hours(int z)
{
hour+=z;
if(hour>=24)
{
hour=hour%24;
}

}
void time::add_minutes(int y)
{
minute+=y;
if(minute>=60)
{
hour+=minute/60;
minute=minute%60;
}

}
void time::add_seconds(int x)
{
sec+=x;
if(sec>=60)
{
minute+=sec/60;
sec=sec%60;
}

}
void time::changefrom0()
{
is_24=!is_24;
}
void time::change24()
{
from0=!from0;
}
int main()
{
time t1(23,14,25);
time t2(8,45,6);
cout<<"24时制，不前导0：\n";
t1.show_time();
t2.show_time();

cout<<"10小时后，切换是否前导0：\n";
t1.add_hours(10);
t2.add_hours(10);
time::change24();
cout<<"t1: ";
t1.show_time();
cout<<"t2: ";
t2.show_time();

cout<<"换一种时制：\n";
time::changefrom0();
cout<<"t1: ";
t1.show_time();
cout<<"t2: ";
t2.show_time();

}