Kolokwium_07

/*
Wypożyczalnia samochodów id i data w kolejce
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define CAR_NAME_SIZE 20

struct queue_node{
    unsigned int id;
    char make[CAR_NAME_SIZE];
    struct queue_node *next;
};

struct queue_pointers{
    struct queue_node *head, *tail;
} fifo;

void enqueue(struct queue_pointers *fifo, unsigned int id, char *make)
{
    struct queue_node *new_node = (struct queue_node*)malloc(sizeof(struct queue_node));
    if(new_node){
        new_node->id = id;
        strncpy(new_node->make, make, CAR_NAME_SIZE);
        new_node->next = NULL;
        if(fifo->head == NULL)
            fifo->head = fifo->tail = new_node;
        else{
            fifo->tail->next = new_node;
            fifo->tail = new_node;
        }
    }
}

int dequeue(struct queue_pointers *fifo)
{
    if(fifo->head){
        struct queue_node *tmp = fifo->head->next;
        int tmp_id = fifo->head->id;
        free(fifo->head);
        fifo->head = tmp;
        if(tmp == NULL)
            fifo->tail = NULL;
        return tmp_id;
    }
    return -1;
}

void print_queue(struct queue_pointers fifo)
{
    while(fifo.head){
        printf("%u: %s\n", fifo.head->id, fifo.head->make);
        fifo.head = fifo.head->next;
    }
    printf("\n");
}

int main(void)
{
    puts("Lista dostepnych samochodow:");
    enqueue(&fifo, 1, "Samochod 1");
    enqueue(&fifo, 2, "Samochod 2");
    enqueue(&fifo, 3, "Samochod 3");
    print_queue(fifo);
    puts("Wypozyczam pierwszy samochod:");
    dequeue(&fifo);
    print_queue(fifo);
    return 0;
}