p7_11.cpp

相当丰富的C++源码

/*****************************
*   p7_11.cpp                 *
*  计算火车旅途时间的友元类  *
*****************************/
#include <iostream>
using namespace std;
class TrainTrip;       //前向引用声明
class Clock {
    private:
      int H,M,S;
    public: 
      void ShowTime()
	  {
         cout<<H<<":"<<M<<":"<<S<<endl;
	  }
	  void SetTime(int H=0,int M=0,int S=0)
	  {
          this->H=H, this->M=M, this->S=S;
	  }
	  Clock(int H=0,int M=0,int S=0)
	  {
         this->H=H, this->M=M, this->S=S;
	  }
	  friend class TrainTrip;
 };
class TrainTrip {
    private:
	   char *TrainNo;    //车次
	   Clock StartTime;  //出发时间
	   Clock EndTime;    //到达时间
	public:
       TrainTrip(char * TrainNo, Clock S, Clock E)
	   {
		  this->TrainNo=TrainNo;
          StartTime=S;
		  EndTime=E;
	   }
      Clock TripTime()
	  {
		 int tH,tM,tS;   //临时存储小时、分、秒数
		 int carry=0;    //借位
		 Clock tTime;    //临时存储时间
		 (tS=EndTime.S-StartTime.S)>0?carry=0:tS+=60,carry=1;
         (tM=EndTime.M-StartTime.M-carry)>0?carry=0:tM+=60,carry=1;
         (tH=EndTime.H-StartTime.H-carry)>0?carry=0:tH+=24;
		 tTime.SetTime(tH,tM,tS);
         return tTime;
	  }    
};
void main()
{
	Clock C1(8,10,10), C2(6,1,2);	//定义Clock类的对象
	Clock C3;                       //定义Clock类对象，存储结果
	TrainTrip T1("K16",C1,C2);	    //定义TrainTrip对象       
	C3=T1.TripTime();
	C3.ShowTime();
}