Replace long with int in the C version to improve performance.

#include <stdlib.h>

#include <math.h>

int isPrime(unsigned long x)

int isPrime(unsigned int x)

{

    if (sqrt(x) - (unsigned long)sqrt(x) == 0)

    if (sqrt(x) - (unsigned int)sqrt(x) == 0)

        return 0;

    for (unsigned long i = 2; i < ceil(sqrt(x)); i++)

    for (unsigned int i = 2; i < ceil(sqrt(x)); i++)

        if (x % i == 0)

            return 0;

    return 1;

int main( int argc, char** argv)

{

    unsigned long max = atol(argv[1]);

    unsigned long *a = malloc(sizeof(unsigned long) * max);

    unsigned long x = 2;

    for (unsigned long i = 0; i < max; x++)

    unsigned int max = atol(argv[1]);

    unsigned int *a = malloc(sizeof(unsigned int) * max);

    unsigned int x = 2;

    for (unsigned int i = 0; i < max; x++)

        if (isPrime(x))

            a[i++] = x;

    for (unsigned long i = 0; i < max; i++)

        printf("%lu\n", (unsigned long)a[i]);

    for (unsigned int i = 0; i < max; i++)

        printf("%u\n", (unsigned int)a[i]);

    return 0;

}