Bingo! - multimi

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

typedef struct NOD{
    int nr;
    struct NOD *next;
}NOD;

NOD *creare_nod(int nr){
    NOD *nod_nou = malloc(sizeof(NOD));
    nod_nou -> nr = nr;
    nod_nou -> next = NULL;
    return nod_nou;
}

NOD *adauga_numar(NOD *head, int nr){
    NOD *nr_nou = creare_nod(nr), *nod = head;

    if(head == NULL)
        return nr_nou;
    if(head -> nr > nr){
        nr_nou -> next = head;
        return nr_nou;
    }
    while(nod->next && nod ->next ->nr < nr) nod = nod-> next;
    nr_nou -> next = nod->next;
    nod -> next = nr_nou;

    return head;
}

void afisare_lista(NOD *head){
    NOD *nod = head;

    for(; nod; nod = nod->next)
        printf("%d ", nod->nr);
}

struct NOD *sterge_nod(NOD *head, NOD *sters){
    NOD *nod = head;
    if(head == sters){
        head = head -> next;
        free(sters);
        return head;
    }

    for(; nod -> next != sters; nod = nod -> next);
    nod -> next = nod -> next -> next;
    free(sters);
    return head;
}

NOD *diferenta(NOD *head1, NOD *head2){

    for(NOD *nod2 = head2; nod2; nod2 = nod2 -> next)
        for(NOD *nod1 = head1; nod1; nod1 = nod1 ->next)
            if(nod1 -> nr == nod2 -> nr){
                head1 = sterge_nod(head1, nod1);
                break;
            }
    return head1;
}

int main(){
    int n, numar;
    NOD *bunica, *numere;
    scanf("%d", &n);

    for(int i = 0; i< n*n; i++){
        scanf("%d", &numar);
        bunica = adauga_numar(bunica, numar);
    }


    while(scanf("%d", &numar) != EOF){
        numere = adauga_numar(numere, numar);
    }

    bunica = diferenta(bunica, numere);

    if(bunica == NULL)
        printf("BINGO!");
    else
        afisare_lista(bunica);
    return 0;
}