Tema liste teza

#include <iostream>
#include <string.h>

using namespace std;

/*struct nod{
    char *nume;
    nod* leg;
};*/

struct nod {
    int info;
    nod *anterior;
    nod *urmator;
    char caracter;
    char nume[];
};

nod *creare(){
    int n;
    cin>>n;
    if (n==0)
        return 0;
    else{
        nod *p=new nod;
        p->info=n;
        p->anterior=NULL;
        nod *prim=p;
        cin>>n;
        while (n){
            nod *q=new nod;
            q->info=n;
            q->anterior=p;
            p->urmator=q;
            p=q;
            cin>>n;
        }
        p->urmator=NULL;
        return prim;
    }
}

void afisare (nod *prim){
    while (prim){
        cout<<prim->info<<" ";
        prim=prim->urmator;
    }
}

void inserare(int k, nod*& prim){
    nod *p=new nod;
    nod *q=prim;
    p->info=0;
    if (k==1){
        p->anterior=NULL;
        p->urmator=prim;
        prim=p;
    }
    else{
        int ind=1;
        q=q->urmator;
        while (q){
            ind++;
            if (ind==k){
                p->urmator=q->urmator;
                q->urmator=p;
                p->anterior=q;

            }
            q=q->urmator;
        }
    }
}
int main()
{
    int pb;
    cout<<"Introdu numatul problemei:"; cin>>pb;
    switch(pb){
        case 1:{ //pb 5, Var. 31
            break;
        }
        case 2:{//pb. 5 Var 33
            nod *prim=creare();
            nod *p=prim;
            int poz=0;
            while (p){
                poz++;
                if (p->info<0){
                    inserare (poz, prim);
                }
                p=p->urmator;
            }
            afisare(prim);
            break;
        }
        case 3:{ //pb 5, Var 53
            int n, a, r;
            cout<<"n="; cin>>n;
            cout<<"a="; cin>>a;
            cout<<"r="; cin>>r;
            nod* prim=new nod;
            prim->info=a;
            nod *q=prim;
            a+=r;
            for (int i=1; i<n; i++, a+=r){
                nod*p=new nod;
                p->info=a;
                q->urmator=p;
                q=p;
            }
            q->urmator=NULL;
            afisare(prim);
            break;
        }
        case 4:{//pb. 5, Var. 91
            char c[20];
            cin>>c;
            nod *prim=new nod;
            prim->caracter=c[strlen(c)];
            prim->anterior=NULL;
            nod *p=prim;
            for (int i=strlen(c)-1; i>=0; i--){
                nod *q=new nod;
                q->caracter=c[i];
                cout<<q->caracter<<" ";
                q->anterior=p;
                p->urmator=q;
                q=p;
            }
            p->urmator=NULL;
            while (prim){
                cout<<prim->caracter<<" ";
                prim=prim->urmator;
            }
            break;
        }
    }
    return 0;
}