BST

#include <bits/stdc++.h>

using namespace std;

ifstream fin ("text.in");
ofstream fout ("text.out");

struct Tree {
  int info;
  Tree *parent, *left, *right;
};

Tree *tree;

void Insert (Tree **l, int x, Tree *parent) {
  Tree *p;
  if (*l == NULL) {
    p = new Tree;
    p -> info = x;
    p -> left = p -> right = nullptr;
    p -> parent = parent;
    *l = p;
    return;
  }
  if (x < (*l) -> info)
    Insert (&((*l) -> left), x, *l);
  else
    Insert (&((*l) -> right), x, *l);
}

Tree *Search (Tree *l, int x) {
  if (l == nullptr)
    return nullptr;
  if (l -> info == x)
    return l;
  if (x < l -> info)
    return Search (l -> left, x);
  else
    return Search (l -> right, x);
}

Tree *Minimum (Tree *T) {
  Tree *Min;
  if (T == nullptr)
    return nullptr;
  Min = T;
  while (Min -> left != nullptr)
    Min = Min -> left;
  return Min;
}

Tree *Maximum (Tree *T) {
  Tree *Max;
  if (T == nullptr)
    return nullptr;
  Max = T;
  while (Max -> right != nullptr)
    Max = Max -> right;
  return Max;
}

void InOrder_traversal (Tree *l) {
  if (l != nullptr) {
    InOrder_traversal(l -> left);
    fout << l -> info << ' ';
    InOrder_traversal(l -> right);
  }
}

void PreOrder_traversal (Tree *l) {
  if (l != nullptr) {
    fout << l -> info << ' ';
    PreOrder_traversal(l -> left);
    PreOrder_traversal(l -> right);
  }
}

void PostOrder_traversal (Tree *l) {
  if (l != nullptr) {
    PostOrder_traversal(l -> left);
    PostOrder_traversal(l -> right);
    fout << l -> info << ' ';
  }
}

int main () {
  Insert (&tree, 2, nullptr);
  Insert (&tree, 5, nullptr);
  Insert (&tree, 7, nullptr);
  Insert (&tree, 8, nullptr);
  Insert (&tree, 9, nullptr);
  Tree *node = Minimum (tree);
  fout << node -> info;
  fout << '\n';
  Tree *Node = Maximum (tree);
  fout << Node -> info;
  fout << '\n';
  InOrder_traversal(tree);
  fout << '\n';
  PreOrder_traversal(tree);
  fout << '\n';
  PostOrder_traversal(tree);
  fout << '\n';
  Tree *nod = Search (tree, 2);
  if (nod != nullptr)
    fout << "YES\n";
  else
    fout << "NO\n";
  Tree *Nod = Search (tree, 10);
  if (Nod != nullptr)
    fout << "YES\n";
  else
    fout << "NO\n";
  return 0;
}