时间

#include <iostream>   using namespace std;  class Time{      public:          void set_time();          void show_time();          inline void add_a_sec();//增加1秒钟           inline void add_a_minute();//增加1分钟           inline void add_a_hour();//增加1小时       private:          bool is_time(int ,int ,int );          int hour;          int minute;          int sec;  };  inline void Time::add_a_sec(){      sec+=1;      if(sec>59){          sec=0;          add_a_minute();      }      return;  }  inline void Time::add_a_minute(){      minute+=1;      if(minute>59){          minute=0;          add_a_hour();      }      return;  }  inline void Time::add_a_hour(){      hour+=1;      if(hour>23)          hour=0;      return;  }  void Time::set_time(){      char c1,c2;      cout<<"情输入时间(格式hh:mm:ss)";      while(1){          cin>>hour>>c1>>minute>>c2>>sec;          if(c1!=':'||c2!=':')              cout<<"格式不正确，情重新输入。"<<endl;          else if(!is_time(hour,minute,sec))              cout<<"时间非法，情重新输入。"<<endl;          else              break;      }  }   void Time::show_time(){      cout<<hour<<":"<<minute<<":"<<sec<<endl;  }bool Time::is_time(int h,int m,int s){      if(h<0||h>24||m<0||m>60||s<0||s>60)          return false;      else          return true;  }  int main(){      Time t1;      Time &t2=t1;      t1.set_time();      cout<<"增加1小时1分钟1秒后"<<endl;      t1.add_a_sec();      t1.add_a_minute();      t1.add_a_hour();      t2.show_time();      return 0;  }