#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#define PRIMELISTSIZE 100000

int uppercheck = 0;

int is_prime(int c, int m, int *primes) {
    int i, p;

    for (i = 0; i <= m; i++)
    {
        p = primes[i];
        if (c % p == 0)
        {
            return(1);
        }
    }
    return(0);
}

int main(int argc, char **argv) {
    int i, square;
    int curListLength = 1;
    int primelistsize = PRIMELISTSIZE;

    int opt;

    // put ':' in the starting of the
    // string so that program can
    //distinguish between '?' and ':'

    while((opt = getopt(argc, argv, "m:")) != -1)
    {
        switch(opt)
        {
            case 'm':
                primelistsize = atoi(optarg);
                break;
            case ':':
                printf("option needs a value\n");
                break;
        }
    }

    // optind is for the extra arguments
    // which are not parsed
    for(; optind < argc; optind++){
        printf("extra arguments: %s\n", argv[optind]);
    }

    int primes[primelistsize];
    primes[0] = 2;
    int candidate = 3;

    square = primes[uppercheck] * primes[uppercheck];
    while (curListLength < primelistsize)
    {

        if (square <  candidate) {
            uppercheck++;
            square = primes[uppercheck] * primes[uppercheck];
        }

        if (is_prime(candidate, uppercheck, primes) == 0)
            {
                primes[curListLength] = candidate; curListLength++;
            }
        candidate += 2;
    }

    for (i = 0; i < primelistsize; i++)
        printf("%d\n", primes[i]);
}