diff --git a/exercise1/node.cpp b/exercise1/node.cpp
index 7f4a0fe..cdacd26 100644
--- a/exercise1/node.cpp
+++ b/exercise1/node.cpp
@@ -1,79 +1,92 @@
 #include "node.h"
+#include <set>
 
 uint32_t Node::node_id = 0;
 
 Node::Node(const std::string &name)
 {
-    node_id++;
+    ++this->node_id;
+    this->name = name;
+}
 
-    if (name.empty())
-    {
-        std::stringstream str_sm;
-        str_sm << node_id;
-        std::string node_id_str = str_sm.str();
+Node::Node()
+{
+    ++this->node_id;
 
-        this->name = "node" + node_id_str;
-    }
-    else
-    {
-        this->name = name;
-    }
+    std::stringstream str_sm;
+    str_sm << "node_";
+    str_sm << this->node_id;
+    this->name = str_sm.str();
 }
 
 Node::~Node()
 {
-    std::cout << "enter ~node() of \"" << name << "\"" << std::endl;
+    std::cout << "enter ~node() of \"" << this->name << "\"" << std::endl;
 
-    for (Node *child : children)
+    for (Node *child : this->children)
     {
         delete child;
     }
 
-    std::cout << "leave ~node() of \"" << name << "\"" << std::endl;
+    std::cout << "leave ~node() of \"" << this->name << "\"" << std::endl;
 }
 
 std::string Node::get_name() const
 {
-    return name;
+    return this->name;
 }
 
 void Node::set_name(const std::string &new_name)
 {
-    name = new_name;
+    this->name = new_name;
 }
 
 int Node::get_nr_children() const
 {
-    return children.size();
+    return this->children.size();
 }
 
 Node *Node::get_child(int i) const
 {
-    if (i < 0 || i >= static_cast<int>(children.size()))
+    if (i < 0 || i >= static_cast<int>(this->children.size()))
     {
         return nullptr;
     }
 
-    return children[i];
+    return this->children[i];
 }
 
-void Node::add_child(Node *child)
-{
-    children.emplace_back(child);
+void Node::add_child(Node* child) {
+  this->children.emplace_back(child);
 }
 
-void Node::print(std::ostream &str, uint32_t depth) const
+void Node::print(std::ostream& stream) const
 {
-    auto predicate = [&str](const Node *node, uint32_t depth) {
-        for (uint32_t i = 0; i < depth; i++)
+    std::set<const Node*> set;
+    this->print(stream, 0, set);
+};
+
+// std::string(times, " ");
+void Node::print(std::ostream& stream, int level, std::set<const Node*>& set) const
+{
+    int i = 0;
+    int count = this->get_nr_children();
+
+    if (set.find(this) != set.end())
+    {
+        stream << repeat(" ", level * 3) << this->get_name() << " (cycle)" << std::endl;
+    }
+    else
+    {
+        set.insert(this);
+
+        stream << repeat(" ", level * 3) << this->get_name() << std::endl;
+
+        for (; i < count; ++i)
         {
-            str << "\t";
+            this->get_child(i)->print(stream, level + 1, set);
         }
-
-        str << node->get_name() + "\n";
-    };
-
-    Node::traverse_tree(this, predicate, false);
+    }
 }
 
 Node *Node::create_complete_tree(uint32_t nr_child_nodes, uint32_t tree_depth)
@@ -83,18 +96,16 @@ Node *Node::create_complete_tree(uint32_t nr_child_nodes, uint32_t tree_depth)
         return nullptr;
     }
 
-    Node *node = new Node;
+    Node* node = new Node();
 
-    for (uint32_t j = 0; j < nr_child_nodes; j++)
+    if (tree_depth == 1)
     {
-        Node *child = Node::create_complete_tree(nr_child_nodes, tree_depth - 1);
+        return node;
+    }
 
-        if (child == nullptr)
-        {
-            break;
-        }
-
-        node->children.emplace_back(child);
+    for (uint32_t i = 0; i < nr_child_nodes; ++i)
+    {
+        node->add_child(create_complete_tree(nr_child_nodes, tree_depth - 1));
     }
 
     return node;
@@ -176,4 +187,15 @@ std::ostream &operator<<(std::ostream &os, const Node *node)
     node->print(os);
 
     return os;
-}
\ No newline at end of file
+}
+
+std::string repeat(std::string value, int times)
+{
+    std::stringstream str_sm;
+
+    for (int i = 0; i < times; ++i) {
+      str_sm << value;
+    }
+
+    return str_sm.str();
+}