FIFO

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


#define STACK_SIZE 100
int *adressen[STACK_SIZE];

//Store value at end of stack
int push(int value) {
    if (endofstack() <= STACK_SIZE)
    {
        adressen[endofstack()] = malloc(sizeof(int));
        *adressen[endofstack() - 1] = value;
        return 1;
    }
    else
    {
        return 0;
    }
}

//return the first value of the stack and shift all to the left
int pop() {
    int value = *adressen[0];

    for (int i = 0; i < STACK_SIZE; i++)
    {
        adressen[i] = adressen[i + 1];
    }
    adressen[STACK_SIZE] = NULL;
    return value;
}

//return the position of the end of the stack (empty adresses filled with NULL)
int endofstack() {
    int i = 0;
    while (adressen[i] != NULL) {
        i++;
    }
    return i;
}

int main() {
    for (int i = 0; i < STACK_SIZE; i++)
    {
        adressen[i] = NULL;
    }
    push(123);
    printf("%d\n", pop());

    for (int i = 0; endofstack() < STACK_SIZE; i++)
    {
        push(i);
    }

    while (endofstack() > 0) {
        printf("%d\n", pop());
    }

    system("PAUSE");

}