p7_10.cpp

来自「相当丰富的C++源码」· C++ 代码 · 共 42 行

/******************************
*   p7_10.cpp                  *
*  计算火车旅途时间的友元函数  *
*******************************/
#include <iostream>
using namespace std;
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 Clock TripTime(Clock & StartTime, Clock & EndTime);
 };
Clock TripTime(Clock & StartTime, Clock & EndTime)
{
	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     
	C3=TripTime(C1,C2);
	C3.ShowTime();
}