使用QueryPerformanceFrequency 计算程序执行时间

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#include <iostream>

#include <windows.h>

using namespace std;

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void main()

{

_LARGE_INTEGER time_start; /*开始时间*/

_LARGE_INTEGER time_over; /*结束时间*/

double dqFreq; /*计时器频率*/

LARGE_INTEGER f; /*计时器频率*/

QueryPerformanceFrequency(&f);

dqFreq=(double)f.QuadPart;

QueryPerformanceCounter(&time_start);

Sleep(1000);/*循环耗时*/

QueryPerformanceCounter(&time_over);

cout<<((time_over.QuadPart-time_start.QuadPart)/dqFreq)<<endl;//单位为秒，精度为1000 000/（cpu主频）微秒

}