#include<iostream.h> 
class Time 
{ 
  int hour,minute,second; 
public: 
  Time(){} 
  Time(int h,int m,int s) 
  { 
   hour=h;minute=m;second=s; 
  } 
  Time(int h,int m) 
  { 
   hour=h;minute=m;second=0; 
  } 
  void sethour(int h){hour=h;} 
  void setminute(int m){minute=m;} 
  void setsecond(int s){second=s;} 
  int gethour(){return hour;} 
  int getminute(){return minute;} 
  int getsecond(){return second;} 
  Time operator+(Time); 
  Time operator-(Time); 
  void disp() 
  { 
   cout<<hour<<":"<<minute<<":"<<second<<endl; 
  } 
}; 
Time Time::operator+(Time t) 
{ 
 int carry,hh,mm,ss; 
 ss=getsecond()+t.getsecond(); 
 if(ss>60) 
 { 
  ss-=60; 
  carry=1; // 進(jìn)位標(biāo)記 
 } 
 else carry=0; 
 mm=getminute()+t.getminute()+carry; 
 if(mm>60) 
 { 
  mm-=60; 
  carry=1; 
 } 
 else carry=0; 
 hh=gethour()+t.gethour()+carry; 
 if(hh>24) 
  hh=24; 
 static Time result(hh,mm,ss); 
 return result; 
} 
Time Time::operator-(Time t) 
{ 
  int borrow,hh,mm,ss; 
  ss=getsecond()-t.getsecond(); 
  if(ss<0) 
  { 
   ss+=60; 
   borrow=1; // 借位標(biāo)記 
  } 
  else borrow=1; 
  mm=getminute()-t.getminute()-borrow; 
  if(mm<0) 
  { 
   mm+=60; 
   borrow=1; 
  } 
  else borrow=0; 
  hh=gethour()-t.gethour()-borrow; 
  if(hh<0) 
   hh+=24; 
  static Time result(hh,mm,ss); 
  return result; 
} 
void main() 
{ 
Time now(2,24,39); 
Time start(17,55); 
Time t1=now-start,t2=now+start; 
cout<<"輸出結(jié)果:"<<endl; 
cout<<" now: "; now.disp(); 
cout<<" start:"; start.disp(); 
cout<<" 相差: "; t1.disp(); 
cout<<" 相加: "; t2.disp(); 
}