计算循环执行的时间

[yuga]

我想做100次的比对，想知道它执行的时间；用了GetLocalTime函数，如下
int i,sum=0,time;
SYSTEMTIME* lpSystemTime;
WORD wMilliseconds=0;
GetLocalTime(lpSystemTime);
time=wMilliseconds;
for(i=0;i<=1000;i++)
sum+=i;
GetLocalTime(lpSystemTime);
time=wMilliseconds-time;
可系统总是说0xcccccccc单元不能为written
那位大哥帮忙

[masterz]

SYSTEMTIME SystemTime;
GetLocalTime(&SystemTime);

precision of GetLocalTime is not enough for this purpose. you'd better try QueryPerformanceCounter(...)

[dolphi]

简单点，用GetTickCount();

....
int Time1 = GetTickCount();
for(;;)
{
....
}
int Interval = GetTickCount() - Time1;

你的问题是lpSystemTime没有分配内存。应该变成
int i,sum=0,time;
SYSTEMTIME SystemTime;
WORD wMilliseconds=0;
GetLocalTime(&lpSystemTime);
time=lpSystemTime.wMilliseconds;
for(i=0;i<=1000;i++)
sum+=i;
GetLocalTime(&SystemTime);
time=lpSystemTime.wMilliseconds-time;