#include <iostream>
using namespace std;

struct btree
{
  int val;
  btree *ltree, *rtree;
};

btree *create_btree(btree *t, int n) {
char c ;
if (t == NULL) { t = new btree ;
t->val = n ;
t->ltree = NULL ;
t->rtree = NULL ;
}
else { cout << "vuoi inserire a sx o a dx (s/d)?: " ;
cin >> c ;
if (c=='s') t->ltree = create_btree(t->ltree,n) ;
else t->rtree = create_btree(t->rtree,n) ;
}
return(t) ;
}

void visit(btree *t){
if (t != NULL) {
cout << t->val ;
visit(t->ltree) ;
visit(t->rtree) ;
}
}

int main ()
{
   btree *p;
   int i;
   for ( i = 0; i < 10 ; i = i + 1)
   {
     p =  create_btree(p, i);
   }
   visit(p);
   return (0);
}