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

#define limit 100 /*size of integers array*/

int main()
{
    unsigned long long int i,j;
    int *primes;
    int z = 1;
    primes = malloc(sizeof(int) * limit);
    for (i = 2; i < limit; i++)
        primes[i] = 1;
    for (i = 2; i < limit; i++)
        if (primes[i])
            for (j = i; i * j < limit; j++)
                primes[i * j] = 0;
    printf("\nPrime numbers in range 1 to 100 are: \n");
    for (i = 2; i < limit; i++)
        if (primes[i])
            printf("%d\n", i);
    return 0;
}