eliminazione_lista_bidirezionale

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

struct node
{
    int data;
    struct node* next;
    struct node* prev;
};

typedef struct node Node;
typedef Node* pNode;

pNode eliminazione_lista_bidirezionale(pNode lista, int elem)
{
    pNode prec,curr;
    curr=lista;

    while(curr!=NULL && elem > curr->data)
        {
            curr=curr->next;
        }

    if(curr->data == elem)
        {
            if(curr->prev==NULL)///in testa
                {
                    lista=curr->next;
                    lista->prev=NULL;
                    free(curr);
                }
            else if(curr->next==NULL)///in fondo
            {
                prec=curr->prev;
                prec->next=NULL;
                free(curr);
            }
            else ///in mezzo
                {
                    prec=curr->prev;
                    prec->next=curr->next;
                    free(curr);
                }
        }
    return lista;
}