diff --git a/set.cpp b/set.cpp
new file mode 100644
index 0000000..36af565
--- /dev/null
+++ b/set.cpp
@@ -0,0 +1,301 @@
+/**
+ * Implementujte metodu insert (vkládání), erase (mazání prvků
+ * ze stromu a zároveň je potřeba uchovat správné pořádí podle
+ * data vkládání) a vlastní destruktor, ostatní metody jsou
+ * naimplentované. Kopírující konstruktor i operátor přiřazení
+ * zakázán. Není povolené si přidat žádnou členskou proměnnou,
+ * ale lze naimplementovat vlastní pomocné metody.
+ *
+ * Za správnost šablony neručím :-).
+ */
+ 
+#include <string>
+#include <cassert>
+ 
+ // https://fit-wiki.cz/%C5%A1kola/p%C5%99edm%C4%9Bty/bi-pa2/pa2_zkou%C5%A1ka_2022-06-16
+
+using namespace std;
+ 
+class CTree
+{
+  public:
+    CTree() = default;
+    ~CTree() {
+        CNode* i = m_First;
+        while (i) {
+            CNode* j = i->m_NextOrder;
+            delete i;
+            i = j;
+        }
+    }
+
+    
+
+    CTree(const CTree &src) = delete;
+
+    bool operator=(const CTree &other) = delete;
+
+    bool isSet(string key) {
+      CNode * n = m_Root;
+      while (n) {
+        if (key == n->m_Key)
+          return true;
+        else if (key > n->m_Key)
+          n = n->m_R;
+        else
+          n = n->m_L;
+      }
+      return false;
+    }
+
+    bool insert(string key) {
+        if (!m_Root)
+            return m_Root = m_First = m_Last = new CNode(key);
+        
+        CNode* i = nullptr;
+        CNode* n = m_Root;
+        while (n) {
+            if (key == n->m_Key) {
+                return false;
+            } else if (key > n->m_Key) {
+                i = n;
+                n = n->m_R;
+            } else {
+                i = n;
+                n = n->m_L;
+            }
+        }
+
+        n = new CNode(key);
+        if (key > i->m_Key)
+            i->m_R = n;
+        else
+            i->m_L = n;
+        
+        n->m_PrevOrder = m_Last;
+        m_Last = m_Last->m_NextOrder = n;
+        return true;
+    }
+    
+    bool erase(string key) {
+        CNode** p = &m_Root;
+        CNode* n = m_Root;
+        while (n) {
+            if (key == n->m_Key)
+                goto found;
+            else if (key > n->m_Key) {
+                p = &n->m_R;
+                n = n->m_R;
+            } else {
+                p = &n->m_L;
+                n = n->m_L;
+            }
+        }
+        return false;
+
+        found:
+        if (!(n->m_L && n->m_R)) { // one or none child
+            *p = (CNode*)((ptrdiff_t)n->m_L | (ptrdiff_t)n->m_R);
+        } else {
+            CNode* ts = n->m_L;
+            CNode** tsp = &n->m_L;
+            while (ts->m_R) {
+                tsp = &ts->m_R;
+                ts = ts->m_R;
+            }
+            swapTree( n, ts );
+            *tsp = ts->m_L;
+            n = ts;
+        }
+        eraseList(n);
+        delete n;
+        return true;
+    }
+
+  protected:
+    class CNode {
+      public:
+        CNode(string key) : m_Key(key) {}
+        string m_Key;
+        CNode * m_L = nullptr;
+        CNode * m_R = nullptr;
+        CNode * m_PrevOrder = nullptr;
+        CNode * m_NextOrder = nullptr;
+    };
+    CNode * m_Root = nullptr;
+    CNode * m_First = nullptr;
+    CNode * m_Last = nullptr;
+
+    void swapTree( CNode* a, CNode* b ) {
+        if      (a == m_Last) m_Last = b;
+        else if (b == m_Last) m_Last = a;
+
+        if      (a == m_First) m_First = b;
+        else if (b == m_First) m_First = a;
+
+        if (a->m_NextOrder) a->m_NextOrder->m_PrevOrder = b;
+        if (a->m_PrevOrder) a->m_PrevOrder->m_NextOrder = b;
+        if (b->m_NextOrder) b->m_NextOrder->m_PrevOrder = a;
+        if (b->m_PrevOrder) b->m_PrevOrder->m_NextOrder = a;
+
+        std::swap(a->m_NextOrder, b->m_NextOrder);
+        std::swap(a->m_PrevOrder, b->m_PrevOrder);
+        std::swap(a->m_Key, b->m_Key);
+    }
+
+    void eraseList( CNode* a ) {
+        if (a->m_PrevOrder) 
+            a->m_PrevOrder->m_NextOrder = a->m_NextOrder;
+        else
+            m_First = a->m_NextOrder;
+    
+        if (a->m_NextOrder) 
+            a->m_NextOrder->m_PrevOrder = a->m_PrevOrder;
+        else
+            m_Last = a->m_PrevOrder;
+    }
+};
+ 
+class CTester : public CTree
+{
+  public:
+    CTester () = default;
+    void test()
+    {
+      CTester t0;
+      assert(t0.insert("PA1")==true);
+      assert(t0.m_First->m_Key=="PA1" && t0.m_First->m_NextOrder == nullptr);
+      assert(t0.isSet("PA1")==true);
+      assert(t0.insert("UOS")==true);
+      assert(t0.insert("PA2")==true);
+      assert(t0.isSet("PA2")==true);
+      assert(t0.isSet("PA3")==false);
+ 
+      assert(t0.insert("PA2")==false);
+      assert(t0.insert("CAO")==true);
+      assert(t0.insert("LIN")==true);
+      assert(t0.insert("AAG")==true);
+      assert(t0.insert("AG1")==true);
+      assert(t0.insert("ZDM")==true);
+ 
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "UOS"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "CAO"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AAG"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "ZDM");
+ 
+      assert(t0.m_Last->m_Key == "ZDM"
+             && t0.m_Last->m_PrevOrder->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "AAG"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "CAO"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "UOS"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+ 
+      assert(t0.erase("")==false);
+ 
+      assert(t0.erase("ZDM")==true);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "UOS"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "CAO"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AAG"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "AAG"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "CAO"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "UOS"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("ZDM")==false);
+ 
+      assert(t0.erase("AAG")==true);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "UOS"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "CAO"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "CAO"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "UOS"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("AAG")==false);
+ 
+      assert(t0.erase("CAO")==true);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "UOS"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "UOS"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("CAO")==false);
+ 
+      assert(t0.erase("UOS")==true);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("UOS")==false);
+ 
+      assert(t0.erase("UOS")==false);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "LIN"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "LIN"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("UOS")==false);
+ 
+      assert(t0.erase("LIN")==true);
+      assert(t0.m_First->m_Key == "PA1"
+             && t0.m_First->m_NextOrder->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "PA2"
+             && t0.m_Last->m_PrevOrder->m_PrevOrder->m_Key == "PA1");
+      assert(t0.isSet("LIN")==false);
+ 
+      assert(t0.erase("PA1")==true);
+      assert(t0.m_First->m_Key == "PA2"
+             && t0.m_First->m_NextOrder->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1"
+             && t0.m_Last->m_PrevOrder->m_Key == "PA2");
+      assert(t0.isSet("PA1")==false);
+ 
+      assert(t0.erase("PA2")==true);
+      assert(t0.m_First->m_Key == "AG1");
+      assert(t0.m_Last->m_Key == "AG1");
+      assert(t0.isSet("PA2")==false);
+ 
+      assert(t0.erase("AG1")==true);
+      assert(t0.m_First == t0.m_Last);
+      assert(t0.isSet("AG1")==false);
+    }
+};
+ #include <iostream>
+int main ( )
+{
+  CTester t;
+  t.test();
+  std::cout << "success!\n";
+  return EXIT_SUCCESS;
+}
\ No newline at end of file