#include <stdlib.h>
#include <stdio.h>
#include "math.h"

/* By Steven Miller, original version '95-'96, modified */
/* version '01. The goal of this program is to read in a */
/* list of primes generated by the program genprime.c and */
/* saved in a file named primedat.fil. */

void main() 
{
 long numprimesless, length, j;
 long primes[50002];
 long sqrtpr[50002];   /* see if you can have larger sizes */

 /* these are all the variables we need for reading. */
 /* genprime.c calculates all the primes up to 50002 */
 /* and saves them in primedat.fil. we of course don't */
 /* need primes to be of size 50002 -- we expect it will */
 /* be of size 50002/log50002 = approx = 5000. The true */
 /* answer is about 5134. So, really, if we can work wi' */
 /* arrays this size, we can calculate and store primes up */
 /* to 10^6. */


 FILE *fpr;

 fpr = fopen("primedat.fil", "r");    /* opens for reading */

 /* the structure of the file primedat.fil is as follows: the first */
 /* entry is the number of primes <= 50002 -- we read that into  */
 /* numprimesless. the next set of numbers are the primes (in order) */
 /* starting wi' 2 and ending wi' the numprimesless prime. we read */
 /* these primes into primes[]. then the next stuff is for sqrts, to */
 /* optimize searching. */

 fscanf(fpr, "%ld ", &numprimesless);
 for (j = 1; j <= numprimesless; ++j)
   {
     fscanf(fpr, "%ld ", &primes[j]);
   }
 fscanf(fpr, "%ld ", &length);
 for (j = 1; j <= length; ++j)
   {
     fscanf(fpr, "%ld ", &sqrtpr[j]);
   }
 fclose(fpr);



 /* this part of the program is for testing / debugging */

 printf("The number of primes is %ld\n", numprimesless);

 for (j = 1; j <= numprimesless; j++)
   printf("prime[%ld] = %ld\n", j, primes[j]); 

 /* this will print all the primes we've saved. the */
 /* number of primes is numprimesless. so, for example, */
 /* we use genprime.c to calculate all the primes up to */
 /* 50002; there are numprimeless such primes, which is */
 /* 5134 or something like that. we then read them in to */
 /* the array primes[], and print */

}