001.linux下clock()检测程序运行时间

#include <stdio.h>
#include <time.h>

int main()
{
int i;
int k;
clock_t start,end;  //clock_t类型实际上为long int类型(4字节)
printf("%d\n",sizeof(long int));
start = clock();
printf("start:%d\n",start);
for(i=0; i<10000000; i++) ;
end = clock();
printf("end:%d\n",end);
printf("%.3fs\n",(double)(end-start)/CLOCKS_PER_SEC); //linux下CLOCKS_PER_SEC=1000000
}