/* a sample program that displays the current execution time. */
#include <stdio.h>
#include <time.h>
void elapsed_time(void);

int main() {
    int i;
    
    clock();    // first call clock
    for(i = 0; i<1000;i++) {};
    elapsed_time();
}

void elapsed_time(void) {
    printf("Elapsed time: %d microsecs.\n",
          clock());  //  return the time between first call
                    //   and this call .
}