primes.c

/* primes.c — Sieve of Eratosthenes for Pactor64 */

#include "libc.h"

#define N 100

int main(int argc, char **argv) {

    printf("=== Prime Numbers (Sieve of Eratosthenes) ===\n");

    printf("Primes up to %d:\n\n  ", N);

    char sieve[N + 1];

    memset(sieve, 1, sizeof(sieve));

    sieve[0] = sieve[1] = 0;

    for (int i = 2; i * i <= N; i++) {

        if (sieve[i]) {

            for (int j = i * i; j <= N; j += i)

                sieve[j] = 0;

        }

    }

    int count = 0;

    for (int i = 2; i <= N; i++) {

        if (sieve[i]) {

            printf("%d ", i);

            count++;

        }

    }

    printf("\n\nTotal: %d primes found.\n", count);

    return 0;

}