//Windows系统下可以用 time()，clock()，timeGetTime()，GetTickCount()，QueryPerformanceCounter()来对一段程序代码进行计时
#include
#include
#include //time_t time() clock_t clock()
#include //timeGetTime()
#pragma comment(lib, "Winmm.lib") //timeGetTime()
//使用方法：将Sleep()函数换成需要测试运行时间的函数即可。
int main()
{ //用time()来计时，以秒为单位
time_t timeBegin, timeEnd;
timeBegin = time(NULL);
Sleep(1000);
timeEnd = time(NULL);
printf("%dn", timeEnd - timeBegin);
//用clock()来计时，以毫秒为单位
clock_t clockBegin, clockEnd;
clockBegin = clock();
Sleep(800);
clockEnd = clock();
printf("%dn", clockEnd - clockBegin);
//用timeGetTime()来计时，以毫秒为单位
DWORD dwBegin, dwEnd;
dwBegin = timeGetTime();
Sleep(800);
dwEnd = timeGetTime();
printf("%dn", dwEnd - dwBegin);
//用GetTickCount()来计时，以毫秒为单位
DWORD dwGTCBegin, dwGTCEnd;
dwGTCBegin = GetTickCount();
Sleep(800);
dwGTCEnd = GetTickCount();
printf("%dn", dwGTCEnd - dwGTCBegin);
//用QueryPerformanceCounter()来计时，以微秒为单位
LARGE_INTEGER large_interger;
double dff;
__int64 c1, c2;
QueryPerformanceFrequency(&large_interger);
dff = large_interger.QuadPart;
QueryPerformanceCounter(&large_interger);
c1 = large_interger.QuadPart;
Sleep(800);
QueryPerformanceCounter(&large_interger);
c2 = large_interger.QuadPart;
printf("本机高精度计时器频率%lfn", dff);
printf("第一次计时器值%I64dn第二次计时器值%I64dn计时器差%I64dn", c1, c2, c2 - c1);
printf("计时%lf毫秒nn", (c2 - c1) * 1000 / dff);
return 0;
}