I know I'm asking pretty basic question here, but could anyone give me a hint how to properly loop through an array which is initialized in another function ? I tried googling, found tons of videos but I didn't manage to get it right just yet. Would anyone please help me find out, what I'm missing in my code ? I'm a struggling beginner. Thanks in advance for your time.

My code (not functioning):

#include <stdio.h>

#define ARR_RANGE 1000000
#define GREATEST_NUMBER 1000000

void sieve(int eratosthenes[]);

int main() 
{
    int eratosthenes[ARR_RANGE];

    int n = 999;
    int c;
    for(i = 2; i <= arrLen;   i)
    {
        if(eratosthenes[i]!= -1)
        {
            int c = 0;
            while(n % i == 0)
            {
                n /= i;
                  c;
            }

            if(c >= 2)
            {
                printf("%d^%d x ", i, c);
            }
            else if(c == 1)
            {
                printf("%d x ", i);
            }
        }
        else
        continue;
    }
    return 0;
}

void sieve(int eratosthenes[])
{
    for(int i = 1; i < GREATEST_NUMBER;   i)
    {
        eratosthenes[i] = i;
    }
    
    for(int i = 2; i*i < GREATEST_NUMBER;   i)
    {
        if(eratosthenes[i] != -1)
        {
            for(int j = 2*i; j < GREATEST_NUMBER ; j  = i)
                eratosthenes[j] = -1;
        }
    }
    
    int arrLen = sizeof eratosthenes / sizeof eratosthenes[0];
}

CodePudding user response：

In the main is not visible the call of function sieve,so the array is not passed into function, to do this you have to write in the main sieve(eratosthenes); (Passage by reference)