diff --git a/tree.cpp b/tree.cpp
index b5dbe81..e4bd95d 100644
--- a/tree.cpp
+++ b/tree.cpp
@@ -1,7 +1,9 @@
 #include<fstream>
 #include<iostream>
 #include<vector>
+#include<set>
 #include<memory>
+#include<cstdlib>
 
 template <typename T>
 struct Node;
@@ -13,6 +15,7 @@ template <typename T>
 struct Node{
     T value;
     int max_depth;
+    int inbalance;
     Node_ptr<T> small;
     Node_ptr<T> big;
 
@@ -20,19 +23,32 @@ struct Node{
     bool add_to_child(Node_ptr<T>* child, T val);
     void update_depth();
     void dump(std::ofstream& ofs) const;
-    Node(T v): value{v}, max_depth{0}, small{nullptr}, big{nullptr}{}
+    Node(T v): value{v}, max_depth{0}, inbalance{0}, small{nullptr}, big{nullptr}{}
 };
 
+
+
+
 template <typename T>
 class Tree{
     Node_ptr<T> root;
+
     Node_ptr<T>* find(T val);
     bool try_to_del(Node_ptr<T>* node, T val);
+    bool try_to_add(Node_ptr<T>* node, T val);
+    void rotate_left(Node_ptr<T>* root);
+    void rotate_right(Node_ptr<T>* root);
+    void balance(Node_ptr<T>* n);
+
+    bool test_insert();
+    bool test_del();
+    bool test_depth(Node_ptr<T>* n);
 
 public:
     bool insert(T val);
     bool del(T val);
     void print() const;
+    bool test();
 };
 
 template <typename T>
@@ -47,37 +63,31 @@ Node_ptr<T>* Tree<T>::find(T val){
 
 template <typename T>
 bool Tree<T>::insert(T val){
-    if(!root){
-        root = std::make_unique<Node<T>>(val);
-        return true;
-    }
-    else return root->add(val);
+    return try_to_add(&root, val);
 }
 
 template <typename T>
-bool Node<T>::add(T val){
-    if (val == value)     return false;
-    else if (val < value) return add_to_child(&small, val);
-    else                  return add_to_child(&big, val);
-}
-
-template <typename T>
-bool Node<T>::add_to_child(Node_ptr<T>* child, T val){
-    if(!(*child)){
-        *child = std::make_unique<Node<T>>(val);
-        update_depth();
+bool Tree<T>::try_to_add(Node_ptr<T>* node, T val){
+    if( ! (*node)){
+        *node = std::make_unique<Node<T>>(val);
+        (*node)->update_depth();
+        balance(node);
         return true;
     }
     else{
-        if((*child)->add(val)){
-            update_depth();
-            return true;
+        if     (val == (*node)->value)           return false;
+        else if(val < (*node)->value){
+            if( ! try_to_add( &(*node)->small, val)) return false;
         }
-        return false;
+        else{//(val > (*node)->value)
+            if( ! try_to_add( &(*node)->big, val))   return false;
+        }
+        (*node)->update_depth();
+        balance(node);
+        return true;
     }
 }
 
-
 template <typename T>
 bool Tree<T>::del(T val){
     if(!root) return false;
@@ -91,7 +101,6 @@ bool Tree<T>::try_to_del(Node_ptr<T>* node, T val){
         std::vector<Node_ptr<T>*> path;
         if((*node)->small) {
             path.push_back(temp);
-            std::cout << "pushing " << (*temp)->value << "\n";
             temp = &(*node)->small;
         }
         else {
@@ -100,7 +109,6 @@ bool Tree<T>::try_to_del(Node_ptr<T>* node, T val){
         }
         while((*temp)->big){
             path.push_back(temp);
-            std::cout << "pushing " << (*temp)->value << "\n";
             temp = &(*temp)->big;
         }
         //mam temp na 'to swap' nodu...
@@ -115,6 +123,7 @@ bool Tree<T>::try_to_del(Node_ptr<T>* node, T val){
         else {
             if(try_to_del(&(*node)->small, val)){
                 (*node)->update_depth();
+                balance(node);
                 return true;
             }
             return false;
@@ -125,6 +134,7 @@ bool Tree<T>::try_to_del(Node_ptr<T>* node, T val){
         else {
             if(try_to_del(&(*node)->big, val)){
                 (*node)->update_depth();
+                balance(node);
                 return true;
             }
             return false;
@@ -133,22 +143,37 @@ bool Tree<T>::try_to_del(Node_ptr<T>* node, T val){
 }
 
 template <typename T>
-void Node<T>::update_depth(){
-    if(small && big) max_depth = std::max(small->max_depth, big->max_depth) + 1;
-    else if (small) max_depth = small->max_depth + 1;
-    else if (big) max_depth = big->max_depth + 1;
-    else max_depth = 0;
+void Tree<T>::rotate_left(Node_ptr<T>* root){
+    Node<T>* new_root = (*root)->big.release();
+    std::swap((*root)->big, new_root->small);
+    new_root->small.reset(root->release());
+    root->reset(new_root);
+
+    if((*root)->small) (*root)->small->update_depth();
+    (*root)->update_depth();
 }
 
 template <typename T>
-void Node<T>::dump(std::ofstream& ofs) const {
-    if (small) {
-        ofs << '"' << value << " : " << max_depth << '"' << " -> "  << '"' << small->value << " : " << small->max_depth << '"' << '\n';
-        small->dump(ofs);
+void Tree<T>::rotate_right(Node_ptr<T>* root){
+    Node<T>* new_root = (*root)->small.release();
+    std::swap((*root)->small, new_root->big);
+    new_root->big.reset(root->release());
+    root->reset(new_root);
+    
+    if( (*root)->big) (*root)->big->update_depth();
+    (*root)->update_depth();
+}
+
+template <typename T>
+void Tree<T>::balance(Node_ptr<T>* n){
+    if((*n)->inbalance >= -1 && (*n)->inbalance <= 1) return;
+    else if ((*n)->inbalance > 1){
+        if((*n)->big && (*n)->big->inbalance == -1) rotate_right(&(*n)->big) ;
+        rotate_left(n) ;
     }
-    if (big) {
-        ofs << '"' << value << " : " << max_depth << '"' << " -> "  << '"' << big->value << " : " << big->max_depth << '"' << '\n';
-        big->dump(ofs);
+    else{
+        if((*n)->small && (*n)->small->inbalance == 1) rotate_left(&(*n)->small);
+        rotate_right(n) ;
     }
 }
 
@@ -164,17 +189,155 @@ void Tree<T>::print() const {
     system("cat viz.dot | dot -Tx11");
 }
 
+template <typename T>
+bool Tree<T>::test(){
+    //vect s opak cisly, zkusim vlozit do stromu i setu a porovnam success, zkontroluju hloubky
+    root.reset();
+    bool ins = test_insert();
+    bool depth = test_depth(&root);
+    bool del = test_del();
+
+    std::cout << "--- INSERTING ---" << "\n";
+    if(ins) std::cout << "\033[92m" << "\t\t" << "... done" << "\033[0m" << "\n";
+    else    std::cout << "\033[91m" << "\t\t" << "... wrong" << "\033[0m" << "\n";
+
+    std::cout << "--- CHECKING DEPTHS ---" << "\n";
+    if(depth) std::cout << "\033[92m" << "\t\t" << "... done" << "\033[0m" << "\n";
+    else    std::cout << "\033[91m" << "\t\t" << "... wrong" << "\033[0m" << "\n";
+
+    std::cout << "--- EREASING ---" << "\n";
+    if(del) std::cout << "\033[92m" << "\t\t" << "... done" << "\033[0m" << "\n";
+    else    std::cout << "\033[91m" << "\t\t" << "... wrong" << "\033[0m" << "\n";
+
+    root.reset();
+    return ins && depth && del;
+}
+
+template <typename T>
+bool Tree<T>::test_insert(){
+    root.reset();
+    std::vector<int> vec;
+    for(int i = 0; i < 10000000; i++){
+        srand(i*3);
+        vec.push_back((rand() % 20000) - 9999);
+    }
+
+    std::set<int> set;
+    size_t prev_set_size = 0;
+    bool tree_ins;
+    // std::cout << "--- FILLING UP ---\n";
+    for(int i = 0; i < 10000000; i++){
+        set.insert(vec[i]);
+        tree_ins = insert(vec[i]);
+        if(tree_ins && set.size() == prev_set_size){
+            // std::cout << "falsely inserted! \n";
+            return false;
+        }
+        else if(!tree_ins && set.size() != prev_set_size){
+            // std::cout << "skipped insert! \n";
+            return false;
+        }
+        else prev_set_size = set.size();
+    }
+    return true;
+}
+
+template <typename T>
+bool Tree<T>::test_del(){
+    root.reset();
+    std::vector<int> vec;
+    std::set<int> set;
+    for(int i = 0; i < 10000000; i++){
+        srand(10000000-i);
+        vec.push_back((rand() % 20000) - 9999);
+        set.insert   ((rand() % 20000) - 9999);
+        insert       ((rand() % 20000) - 9999);
+    }
+    bool set_del;
+    bool tree_del;
+    // std::cout << "--- EMPTYING ---\n";
+    for(int i = 0; i < 10000000; i++){
+        tree_del = del(vec[i]);
+        set_del = set.erase(vec[i]);
+        if(tree_del && !set_del){
+            // std::cout << "falsely deleted! \n";
+            return false;
+        }
+        if(!tree_del && set_del){
+            // std::cout << "skipped delete! \n";
+            return false;
+        }
+    }
+    return true;
+}
+
+template <typename T>
+bool Tree<T>::test_depth(Node_ptr<T>* n){
+    if((*n)->small && (*n)->big){
+        return test_depth(&(*n)->small) &&
+               test_depth(&(*n)->big)    &&
+               (*n)->max_depth == ( std::max((*n)->small->max_depth, (*n)->big->max_depth) + 1 );
+    }
+    else if((*n)->small){
+        return test_depth(&(*n)->small) &&
+               (*n)->max_depth == (*n)->small->max_depth + 1;
+    }
+    else if((*n)->big){
+        return test_depth(&(*n)->big) &&
+               (*n)->max_depth == (*n)->big->max_depth + 1;
+    }
+    else{
+        return (*n)->max_depth == 0;
+    }
+}
+
+
+template <typename T>
+void Node<T>::update_depth(){
+    if (small && big) {
+        max_depth = std::max(small->max_depth, big->max_depth) + 1;
+        inbalance = big->max_depth - small->max_depth;
+    }
+    else if (small) {
+        max_depth = small->max_depth + 1;
+        inbalance =   - small->max_depth - 1;
+    }
+    else if (big)           {
+        max_depth = big->max_depth + 1;
+        inbalance =   big->max_depth + 1;
+    }
+    else {
+        max_depth = 0;
+        inbalance =   0;
+    }
+}
+
+template <typename T>
+void Node<T>::dump(std::ofstream& ofs) const {
+    if (small) {
+        ofs << '"' << value << " : " << inbalance << '"' << " -> "  << '"' << small->value << " : " << small->inbalance << '"' << '\n';
+        small->dump(ofs);
+    }
+    if (big) {
+        ofs << '"' << value << " : " << inbalance << '"' << " -> "  << '"' << big->value << " : " << big->inbalance << '"' << '\n';
+        big->dump(ofs);
+    }
+}
+
 int main(){
     Tree<int> t;
-    std::vector<int> v = {9, 2, 5, 7, 4, 8, -1, 15, 12, 17, 10, 13};
-    for(auto i : v){
-        if(t.insert(i)) std::cout << "added " << i << "\n";
-        else std::cout << "failed at adding " << i << "\n";
-        t.print();
-    }
-    for(auto i : v){
-        if(t.del(i)) std::cout << "deleted " << i << "\n";
-        else std::cout << "failed at deleting " << i << "\n";
-        t.print();
-    }
+    bool test = t.test();
+    if(!test) std::cout << "You're stupid!" << "\n";
+    // std::vector<int> v = {9, 2, 5, 7, 4, 8, -1, 15, 12, 17, 10, 13};
+    // std::cout << "\t" << "toto je odsazene"<< "\n";
+    // for(auto i : v){
+    //     if(t.insert(i)) std::cout << "added " << i << "\n";
+    //     else            std::cout << "failed at adding " << i << "\n";
+    //     t.print();
+    // }
+    // for(auto i : v){
+    //     if(t.del(i)) std::cout << "deleted " << i << "\n";
+    //     else         std::cout << "failed at deleting " << i << "\n";
+    //     t.print();
+    // }
 }
\ No newline at end of file