#include <sys/time.h>
double rtclock() {
  struct timezone Tzp;
  struct timeval Tp;
  int stat;
  stat = gettimeofday(&Tp, &Tzp);
  if (stat != 0) printf("Error return from gettimeofday: %d", stat);
  return(Tp.tv_sec + Tp.tv_usec * 1.0e-6);
}

void printtime(const char *str, double starttime, double endtime) {
	printf("%s%3f seconds\n", str, endtime - starttime);
}