d_timer.h

来自「这是数据结构和算法的国外经典书籍.清华大学出版社出版的<数据结构C++语言」· C头文件 代码 · 共 59 行

#ifndef TIMER_CLASS
#define TIMER_CLASS

#include <time.h> // declares clock_t type, function clock(),
                  // and constant CLOCKS_PER_SEC

class timer
{
   private:

      // starting and ending time measured in clock ticks
      clock_t startTime, endTime;

   public:
      timer();
			// initialize the timer.
			// Postconditions: set the starting and ending event times to 0.
			// this creates an event whose time is 0.0

      void start();
			// start timing an event.
			// Postcondition:	record the current time as the starting time
		void stop();
			// stop timing an event.
			// Postconditon:	record the current time as the ending time
      double time() const;
			// return the time the event took in seconds by computing
			// the difference between the ending and starting times.
};

// ***********************************************************
//      timer class implementation
// ***********************************************************

// constructor. set starting and ending times to 0
timer::timer():startTime(0), endTime(0)
{}

// determine clock ticks at start
void timer::start()
{
   startTime = clock();
}

// determine clock ticks at end
void timer::stop()
{
   endTime = clock();
}

// return the elapsed time in seconds
double timer::time() const
{
   return (endTime-startTime)/double(CLOCKS_PER_SEC);
}

#endif   // TIMER_CLASS