List doesn't exit loops?

Question

I've basically just begun studying lists, and I ran into problems in the first exercises. This is a program to print the elements of the list.

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

struct EL {
    int info;
    struct EL *next;
};
typedef struct EL ElementoLista;
typedef ElementoLista *ListaDiElementi;

void InserisciTestaLista(ListaDiElementi *lista, int elem){
    ListaDiElementi aux;
    aux=malloc(sizeof(ElementoLista));
    aux->info=elem;
    aux->next=*lista;
    *lista=aux;
};

void readListIntRic (ListaDiElementi *L, int K ) {
    int x;
    if (K>0){ 
        printf("Digita un intero elemento della lista\n");
        scanf("%d",&x);
        InserisciTestaLista(L,x);
        readListIntRic(L,K-1);
    } 
};

void stampaLista (ListaDiElementi lista){
    while (lista != NULL){
        printf("%d->",lista->info);
        lista=lista->next;
    }    
    printf("//");
};

int main(){
    ListaDiElementi lista;
    int k;
    printf("Inserisci il numero di elementi di cui vuoi che la lista sia costituita\n");
    scanf("%d",&k);
    readListIntRic(&lista,k);
    stampaLista(lista);
}

The program behaves strangely:

-It prints 0 at the end, even though there is no zero in the list;

-I put the printf("//"); just to see if the program exited the cycle. Turns out, it doesn't.

This is giving me a lot of problems. I've been trying to do other exercises as well, but they all have the same problem and I can't figure out what it is. I'm using the GCC compiler with wxDev-C+

where are you setting actually the last element of the list to be null? — cerkiewny, Aug 12 '14 at 14:26
Get rid of all those `typedef`s. They contribute nothing to the readability of your code (they're making it worse to be more accurate). — barak manos, Aug 12 '14 at 14:27
@barak manos Thanks for the suggestion. I modified my style and it's now much clearer, even logically. — Gennaro Marco Devincenzis, Aug 13 '14 at 14:17

score 3 · Accepted Answer · edited May 23 '17 at 11:57

3

You are not initializing ListaDiElementi lista = NULL; in main(). That's why the while (lista != NULL) loop never ends.

Read Initializing variables in C to learn more about this.

edited May 23 '17 at 11:57

Community

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answered Aug 12 '14 at 14:26

ericbn

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List doesn't exit loops?

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