Do What The Fuck You Want To Public License

Sieb_des_Eratosthenes.c

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#define MAX 80000000

//Sieb des Eratosthenes zur bestimmung von primzahlen
int Sieb_des_Eratosthenes()
{
    long long unsigned int i, j, x;
    x = 0;
    char *array;
    array = calloc((MAX + 1), sizeof(char));
    if (array==NULL) {
       printf("Error allocating memory!\n");
       return -1; //return with failure
    }
    
    for(i = 2; i <= sqrt(MAX); i++)
    {
       if(array[i] == 0)     
       {
           for(j = i * i; j <= MAX; j += i)
           {
                 array[j] = 1;
           }      
       }
    }
    
     for(i = 2; i <= MAX; i++) {
        if (array[i] == 0) {
                   x++;
            }
    }
    
    printf("Primzahlen: %d\n", x);
    
    free(array);
    array = NULL;
    return 0;
}

int main(void)
{
    LARGE_INTEGER frequency;
    LARGE_INTEGER start;
    LARGE_INTEGER end;
    double interval;

    QueryPerformanceFrequency(&frequency);
    QueryPerformanceCounter(&start);
    
    Sieb_des_Eratosthenes();

    QueryPerformanceCounter(&end);
    interval = (double) (end.QuadPart - start.QuadPart) / frequency.QuadPart;

    printf("%f\n", interval);
    
    system("PAUSE");
    return (0);
}