/* standard "sieve of eratosthenes" generation of primes *
 * keyboard entered by frank gaude'  08/02/83 	         */

#include "stdio80.h"

#define SIZE  	8190	/* size of number array */
#define FALSE  	   0
#define TRUE	   1
#define NTIMES	  10

    extern  printf(),exit();
	char	flag[SIZE + 1];

main()		/* compute primes using sieve of eratostenes */
{
	int	i, j, k, count, prime;

	printf("10 iterations: ");

	for (i = 1; i <= NTIMES; i++) {			 /* do program ntimes */
		count = 0;				 /* prime counter     */
		for (j = 0; j <= SIZE; j++)		 /* set all flags true*/
			flag[j] = TRUE;                  
		for (j = 0; j <= SIZE; j++) {            
			if (flag[j] == TRUE) {		 /* found a prime     */
				prime = j + j + 3;	 /* twice index + 3   */
				printf("\n%d",prime);    /* print prime       */
				for (k = j + prime; k <= SIZE; k += prime)
					flag[k] = FALSE; /* discard multiples */
				count++;		 /* primes found      */
			}
		}
	}

	printf("%d primes.\n", count);
	exit(0);
}