de toate pentru test x2

//Citire/parcurgere/cautare arbore binar
struct nod
   {int nr_o;
    nod*st,*dr;
   };

nod *v;
int n,k;

void inserare(nod *&c,int k)
{if(c)
   if(c->nr_o==k)
        cout<<"nr deja inserat "<<endl;
   else
     if(c->nr_o<k)
     inserare(c->dr,k);
     else
     inserare(c->st,k);

 else
     {c=new nod;
      c->nr_o=k;
      c->st=c->dr=0;}
}


void svd(nod *c) //parcurgere in inordine
{if(c)
  {svd(c->st);
   cout<<c->nr_o<<" ";
   svd(c->dr);
  }
 }

int cautare(nod *c,int k)
{if(c)
    if(c->nr_o==k)
    return 1;
    else
    if(c->nr_o<k)
       cautare(c->dr,k);
    else
       cautare(c->st,k);
 else
    return 0;
}
void main()
{//v=0;
 cout<<"nr de noduri ";
 cin>>n;
 for(int i=1;i<=n;i++)
   {cout<<"valoarea de inserat ";
    cin>>k;
    inserare(v,k);}

 cout<<endl<<"arborele are urmatoarele noduri "<<endl;
 svd(v);
 cout<<endl<<"valoarea de cautat ";
 cin>>k;
 if(cautare(v,k))
    cout<<"s-a gasit!";
 else
    cout<<"nu s-a gasit!";
 getch();

}

---------------------------------------------------------

//Creare forma poloneza

#include<iostream>
#include<string.h>
using namespace std;
#define MAX 100
typedef struct nod{
    char inf;
    nod *st,*dr;
}ARB;
char e[MAX],efp[MAX];
int p[MAX],pfp[MAX];
ARB *rad;
void Creare(ARB* &c,int li,int ls,char epf[],int pfp[])
{
    int i,j,min;
    min=pfp[ls]; i=ls;
    for(j=ls;j>=li;j--)
        if(pfp[j]<min) { min=pfp[j]; i=j; }
    c=new ARB; c->inf=efp[i];
    if(li==ls)
        c->st=c->dr=0;
    else
    {
        Creare(c->st,li,i-1,efp,pfp);
        Creare(c->dr,i+1,ls,efp,pfp);
    }
}
void Parcurgere(ARB *c)
{
    if(c)
    {
        cout<<c->inf;Parcurgere(c->st); Parcurgere(c->dr);
    }
}
int main()
{
    int i,j=0;
    cout<<"introduceti expresia: "; gets(e);
    for(i=0;e[i];i++)
        switch(e[i])
    {
        case ')': j-=10; break;
        case '(': j+=10; break;
        case '+':
        case '-': p[i]=j+1; break;
        case '*':
        case '/': p[i]=j+10; break;
        default: p[i]=1000;
    }
    j=-1;
    for(i=0;e[i];i++)
        if(e[i]!=')'&&e[i]!='(')
        {
            j++; efp[j]=e[i]; pfp[j]=p[i];
        }
    Creare(rad,0,j,efp,pfp);
    cout<<"\nForma poloneza prefixata este: ";
    Parcurgere(rad); cout<<"\n";
return 0;
}

-----------------------------
//stergere nod arbore binar
void cmd(nod* &c,nod* &f)
{nod *aux;
 if(f->dr)
    cmd(c,f->dr);
 else
     {c->nr_o=f->nr_o;
      aux=f;
      f=f->st;
      delete aux;
      }
}

void sterg(nod *&c,int k)
{nod *aux,*f;
 if(c)
   if(c->nr_o==k)
       if(c->st==0&&c->dr==0)  //daca e nod terminal
       {delete c;
        c=0;
        }
    else
       if(c->st==0)     //are numai subordonat drept
         {aux=c->dr;
          delete c;
          c=aux;}
        else
           if(c->dr==0)    //are numai subordonat drept
          {aux=c->st;
           delete c;
           c=aux;}
           else
           cmd(c,c->st);  //are ambii subordonati

   else
     if(c->nr_o<k)
    sterg(c->dr,k);
     else
    sterg(c->st,k);

 else
      cout<<"valoarea de sters nu se gaseste in arbore ";
}