// tree.cpp : Defines the entry point for the console application.

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

using namespace std;

struct item {
    int key;
    item* left;
    item* right;
};

item* root=0;

item* search(int k){
    item* p=root;
    while (p!=NULL)
    {
       if (k < p->key)
           p = p->left;
       else if(k > p->key)
           p = p->right;
       else return p;
    }
    return p;
}

item* find (item * p, int k){
    if (p==NULL)
       return NULL;
    else if (k < p->key)
       return find (p->left, k);
    else if (k > p->key)
        return find (p->right, k);
    else return p;
}

void enter (item * & p, int k){
    if (p==NULL)
    {
       item * u = new item;
       u->key = k;
       u->left = NULL;
       u->right = NULL;
       p = u;
    }
    else if (k < p->key)
       enter (p->left, k);
    else if (k > p->key)
       enter (p->right, k);
}

void insert (int k) {
    enter (root, k);
}

void print (item * p)
{
    if (p != nullptr)
    {
        print (p->left);
        cout << p->key << endl;
        print (p->right);
    }
}

void enter2 (item * * p, int k){
    if (*p==NULL)
    {
       item * u = new item;
       u->key = k;
       u->left = NULL;
       u->right = NULL;
       *p = u;
    }
    else if (k < (*p)->key)
       enter ((*p)->left, k);
    else if (k>(*p)->key)
       enter ((*p)->right, k);
}

void enter3 (int k){
    item * * p = & root;
    while (true)
    {
        if (*p==NULL)
        {
           item * u = new item;
           u->key = k;
           u->left = NULL;
           u->right = NULL;
           *p = u;
           return;
        }
        else if (k < (*p)->key)
           p = & ((*p)->left );
        else if (k > (*p)->key)
           p = &	((*p) ->right);
    }
}


int _tmain(int argc, _TCHAR* argv[])
{
    cout << "Hello" << endl;
    insert (7);
    insert (5);
    insert (10);

    enter  (root, 17);
    enter2 (&root, 27);
    enter3 (37);

    print (root);

    cout << "End" << endl;
    system ("pause");

    return 0;
}