static keyword C puzzle :-)

static_puzzle.c

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

int static_puzzle()
{
    static int i = 0;
    for (; i < 10; i++)
    {
        return i;
    }
    return i;
}

int static_puzzle2()
{
    static int i = 0;
    for (; i < 10;)
    {
        return i++;
    }
    return i;
}

int main(int argc, char* argv[])
{
    int val;
    while ((val = static_puzzle2()) < 10)
    {
        fprintf(stdout, "%d\n", val);
        fflush(stdout);
    }

    sleep(5);
    while ((val = static_puzzle()) < 10)
    {
        fprintf(stdout, "%d\n", val);
        fflush(stdout);
    }

    return EXIT_SUCCESS;
}