Random Number Generation At Runtime in c

c --code

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

int main ()
{
  /* initialize random seed: */
  srand ( time(NULL) );

  printf("random number:%d,",rand()%20);
  printf("%d,",rand()%30);
  printf("%d,",rand()%40);
  printf("%d\n",rand()%10);

  return 0;
}