Depou

#include <iostream>

using namespace std;
typedef struct mutare{char deUnde, unde; mutare *urm;};
typedef struct nod{int info; nod *urm;};
nod *stivaA=NULL, *stivaB=NULL;
mutare *capMutari, *sfMutari;
int u=0, nrMutari, i, n, x, ok = 1;
void push(nod*&st,int x)
{
    nod *p=new nod({x,st});
    st=p;
}
int pop(nod *&st)
{
    int x=st->info;
    nod *p=st;
    st=st->urm;
    delete p;
    return x;
}
void add(char deUnde, char unde)
{
    mutare *p = new mutare({deUnde, unde, NULL});
    nrMutari++;
    if(sfMutari == NULL)
        capMutari = p;
      else
        sfMutari->urm = p;
    sfMutari = p;
}
int main()
{
    cin >> n;
    for(i=1; i<=n; i++){ cin >> x; push(stivaA,x); }

    while (u < n && ok == 1)
    {
        // incerc sa mut din A in C
        if(stivaA != NULL && stivaA->info == u + 1)
        {
            u++;
            pop(stivaA);
            add('A','C');
        }
        else //incerc sa mut din B in C
            if(stivaB != NULL && stivaB->info == u + 1)
        {
            u++;
            pop(stivaB);
            add('B','C');
        }
        else // mut din A in B
            if(stivaA!=NULL)
                {push(stivaB,pop(stivaA));add('A','B');}
            else
                ok = 0;
    }
    nrMutari *= ok;
    cout << nrMutari <<"\n";
    if(nrMutari > 0)
    while(capMutari != NULL) { cout<<capMutari->deUnde<<" "<<capMutari->unde<<"\n";capMutari = capMutari->urm;}
    return 0;
}