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

typedef struct item* link;

struct item{
    int val;
    link next;
};
typedef struct{
    link head;
    link tail;
    int n;
}tab;

link newNode(int val, link next);
void insInTail(tab *l, int val);

int main()
{
    int i,c = 0;
    link x, t;
    tab *lista = malloc(sizeof(tab));
    lista->head = NULL;
    lista->tail = NULL;
    lista->n = 0;
    for (i = 0; i<=10; i++)
        insInTail(lista,i);

    for (x = lista->head; x != NULL; x = x->next)
        printf("%d\n", x->val);

    //cancellazione
    for (x=lista->head; x!=NULL; x=x->next) {
        if ((c%2) == 0){
            t = x->next;
            x->next = x->next->next;
            free(t);
        }
        c++;
    }

    for (x = lista->head; x != NULL; x = x->next)
        printf("%d\n", x->val);

    return 0;
return 0;
}
link newNode(int val, link next) {
    link x = malloc(sizeof *x);
    if (x==NULL)
        return NULL;
    x->val = val;
    x->next = next;
    return x;
}
void insInTail(tab *l, int val){
    if (l->head == NULL){
        l->head = l->tail = newNode(val, NULL);
    }
    else{
        l->tail->next = newNode(val, NULL);
        l->tail = l->tail->next;
    }
    return;
}