// file timer.h//created by alpha 2008.11.15#ifndef TIMER_H#define TIMER_H#include <windows.h>class Timer{private:    int _freq;    LARGE_INTEGER _begin;    LARGE_INTEGER _end;public:    long costTime;            // 花費(fèi)的時(shí)間(精確到微秒)public:    Timer()    {        LARGE_INTEGER tmp;        QueryPerformanceFrequency(&tmp);        _freq = tmp.QuadPart;        costTime = 0;    }    void Start()            // 開始計(jì)時(shí)    {        QueryPerformanceCounter(&_begin);    }    void End()                // 結(jié)束計(jì)時(shí)    {        QueryPerformanceCounter(&_end);        costTime = (long)((_end.QuadPart - _begin.QuadPart) * 1000000 / _freq);    }    void Reset()            // 計(jì)時(shí)清0    {        costTime = 0;    }};#endif