File prioritaire.

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

typedef struct ffile ffile;
struct ffile
{
    int data;
    ffile* next;
};
ffile* creer()
{
    return NULL;
}
int vide(ffile *f)
{
    if(f)
        return 0;//correspond a non vide
    else
        return 1;//correspond a vide
}
void enfiler(ffile **f,int x)
{
    ffile* p;
    p=(ffile*)malloc(sizeof(ffile));
    p->data=x;
    p->next=*f;
    *f=p;
}
int defiler(ffile **f)
{
    if(!*f)
    {
        printf("Liste vide \n");
        return -999;//-999 correspond a erreur.
    }
    else if(!(*f)->next)
    {
        int x=(*f)->data;
        free (*f);
        *f=NULL;
        return x;
    }
    else
    {
        ffile *c=*f;
        while(c->next->next)
            c=c->next;
        int x;
        x=c->next->data;
        free(c->next);
        c->next=NULL;
        return x;
    }
}
int affiche(ffile *f)
{
    int i=0;
    while(f){
        printf("l'element %d : %d \n",i+1,f->data);
        i++;
        f=f->next;
    }
    return i;
}
void liberer(ffile **f)
{
    ffile* c=*f;
    while(*f)
    {
        *f=(*f)->next;
        free(c);
        c=(*f);

    }
}
void create(ffile** t)
{
    int i;
    for(i=0;i<4;i++){
        t[i]=NULL;
    }
}
void ajout(ffile **t,int n)
{
    int i;
    printf("Donner la prioritee.\n");
    do{
        scanf("%d",&i);
    }while((i>4)||(i<1));
    enfiler(&t[i-1],n);
}
int deff(ffile **t)
{
    if(t[0])
        return defiler(&t[0]);
    else if(t[1])
        return defiler(&t[1]);
    else if(t[2])
        return defiler(&t[2]);
    else if(t[3])
        return defiler(&t[3]);
    else{
        printf("Erreur\n");
        return -999;//correspond a erreur.
    }
}
vider_stream()
{
    char c;
    while ((c = getchar()) != '\n' && c != EOF);
}
int main()//file a 4 priorite.
{
    ffile* f;
    ffile** t;
    t=malloc(4*sizeof(ffile*));
    create(t);
    ajout(t,1);
    int x=affiche(t[0]);
    printf("%d\n",x);
    x=deff(t);
    printf("%d\n",x);
    printf("%p\n",t[0]);
    return 0;
}

/*f=creer();
    int x;
    char c='a';
    while(c!='Q'){
        printf("Donner la commande\n");
        vider_stream();
        scanf("%c",&c);
        printf("Donner l'element a enfiler.\n");
        scanf("%d",&x);
        enfiler(&f,x);
    }
    int com;
    com=affiche(f);
    printf("Le nombre des elements est %d\n",com);
    liberer(&f);
    printf("%p\n",f);*/