diff --git a/CMakeLists.txt b/CMakeLists.txt
index c86a8b1..3d4692d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -137,6 +137,7 @@ set(APP_SOURCES
     "src/core/datatypes/container/adapter/Queue.cpp"
     "src/core/datatypes/container/adapter/Stack.cpp"
     "src/core/datatypes/container/sequence/Deque.cpp"
+    "src/core/datatypes/container/associative/Set.cpp"
     ## LC
     "src/leetcode/arrays/two_sum/TwoSum.cpp"
     "src/leetcode/arrays/median_two_arrays/MedianTwoSortedArrays.cpp"
diff --git a/src/controller/pid/PIDSim.cpp b/src/controller/pid/PIDSim.cpp
index c54f970..a03f1d8 100644
--- a/src/controller/pid/PIDSim.cpp
+++ b/src/controller/pid/PIDSim.cpp
@@ -2,7 +2,6 @@
 #include "pid.h"
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 void run() {
diff --git a/src/core/basics/ControlFlow.cpp b/src/core/basics/ControlFlow.cpp
index 8a57328..25c2b05 100644
--- a/src/core/basics/ControlFlow.cpp
+++ b/src/core/basics/ControlFlow.cpp
@@ -117,7 +117,6 @@ void exceptions() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class ControlFlow : public IExample {
  public:
diff --git a/src/core/basics/InitializeVariable.cpp b/src/core/basics/InitializeVariable.cpp
index 4410afd..c10602d 100644
--- a/src/core/basics/InitializeVariable.cpp
+++ b/src/core/basics/InitializeVariable.cpp
@@ -2,7 +2,6 @@
 using namespace std;
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 void initialize_variable();
 
diff --git a/src/core/basics/Operations.cpp b/src/core/basics/Operations.cpp
index d123057..e5f4575 100644
--- a/src/core/basics/Operations.cpp
+++ b/src/core/basics/Operations.cpp
@@ -2,7 +2,6 @@
 using namespace std;
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 void arithmeticOperator();
 void logicalOperator();
diff --git a/src/core/basics/TypeQualifier.cpp b/src/core/basics/TypeQualifier.cpp
index 95507d8..1b81de9 100644
--- a/src/core/basics/TypeQualifier.cpp
+++ b/src/core/basics/TypeQualifier.cpp
@@ -31,7 +31,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class TypeQualifier : public IExample {
  public:
diff --git a/src/core/datatypes/CArray.cpp b/src/core/datatypes/CArray.cpp
index 3af858c..cafe1dc 100644
--- a/src/core/datatypes/CArray.cpp
+++ b/src/core/datatypes/CArray.cpp
@@ -1,7 +1,6 @@
 #include <iostream>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 void arrayExamples() {
   std::cout << "\n--- Array Examples ---\n";
diff --git a/src/core/datatypes/CEnum.cpp b/src/core/datatypes/CEnum.cpp
index 13aca53..c705104 100644
--- a/src/core/datatypes/CEnum.cpp
+++ b/src/core/datatypes/CEnum.cpp
@@ -40,7 +40,6 @@ void enums() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CEnum : public IExample {
  public:
diff --git a/src/core/datatypes/CPointers.cpp b/src/core/datatypes/CPointers.cpp
index 1890898..2bbef1f 100644
--- a/src/core/datatypes/CPointers.cpp
+++ b/src/core/datatypes/CPointers.cpp
@@ -104,7 +104,6 @@ void pointers() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CPointers : public IExample {
  public:
diff --git a/src/core/datatypes/CReferences.cpp b/src/core/datatypes/CReferences.cpp
index f8e044d..20a6583 100644
--- a/src/core/datatypes/CReferences.cpp
+++ b/src/core/datatypes/CReferences.cpp
@@ -83,7 +83,6 @@ void run() {
 }  // namespace RvalueReference
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CReferences : public IExample {
  public:
diff --git a/src/core/datatypes/CStruct.cpp b/src/core/datatypes/CStruct.cpp
index b181fb7..a7f311b 100644
--- a/src/core/datatypes/CStruct.cpp
+++ b/src/core/datatypes/CStruct.cpp
@@ -62,7 +62,6 @@ void structs() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CStruct : public IExample {
  public:
diff --git a/src/core/datatypes/CUnion.cpp b/src/core/datatypes/CUnion.cpp
index 7874094..3b48c44 100644
--- a/src/core/datatypes/CUnion.cpp
+++ b/src/core/datatypes/CUnion.cpp
@@ -38,7 +38,6 @@ void unionDemo() {
 
 // --- Auto-run struct ---
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CUnion : public IExample {
  public:
diff --git a/src/core/datatypes/Fundamental.cpp b/src/core/datatypes/Fundamental.cpp
index 919cdf5..a72c9ab 100644
--- a/src/core/datatypes/Fundamental.cpp
+++ b/src/core/datatypes/Fundamental.cpp
@@ -51,7 +51,6 @@ void primative() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Fundamental : public IExample {
  public:
diff --git a/src/core/datatypes/TypeConVersions.cpp b/src/core/datatypes/TypeConVersions.cpp
index 1d2a6d2..9c5ae3e 100644
--- a/src/core/datatypes/TypeConVersions.cpp
+++ b/src/core/datatypes/TypeConVersions.cpp
@@ -145,7 +145,6 @@ void typeDeduction() {
 }
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CTypeConversion : public IExample {
  public:
diff --git a/src/core/datatypes/class/CConstructors.cpp b/src/core/datatypes/class/CConstructors.cpp
index ce0841d..579f018 100644
--- a/src/core/datatypes/class/CConstructors.cpp
+++ b/src/core/datatypes/class/CConstructors.cpp
@@ -303,7 +303,6 @@ void constructers() {
 }  // namespace Move
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CConstructors : public IExample {
  public:
diff --git a/src/core/datatypes/class/CDestructors.cpp b/src/core/datatypes/class/CDestructors.cpp
index 15ce8b9..64bc62b 100644
--- a/src/core/datatypes/class/CDestructors.cpp
+++ b/src/core/datatypes/class/CDestructors.cpp
@@ -58,7 +58,6 @@ void destructers() {
 }  // namespace Virtual
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CDestructors : public IExample {
  public:
diff --git a/src/core/datatypes/class/RoleOfThreeFiveZero.cpp b/src/core/datatypes/class/RoleOfThreeFiveZero.cpp
index 9e4e96d..0f42b94 100644
--- a/src/core/datatypes/class/RoleOfThreeFiveZero.cpp
+++ b/src/core/datatypes/class/RoleOfThreeFiveZero.cpp
@@ -273,7 +273,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class RoleOfThreeFiveZero : public IExample {
  public:
diff --git a/src/core/datatypes/class/SallowDeepCopying.cpp b/src/core/datatypes/class/SallowDeepCopying.cpp
index 845d05b..2577d19 100644
--- a/src/core/datatypes/class/SallowDeepCopying.cpp
+++ b/src/core/datatypes/class/SallowDeepCopying.cpp
@@ -152,7 +152,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class ShallowDeepCopying : public IExample {
  public:
diff --git a/src/core/datatypes/container/README.md b/src/core/datatypes/container/README.md
index 644c4e7..ad52251 100644
--- a/src/core/datatypes/container/README.md
+++ b/src/core/datatypes/container/README.md
@@ -2,7 +2,7 @@
 - The Containers library is a generic collection of class templates and algorithms that allow programmers to easilly implement common data structures.
 - All container functions can be called concurrently by different threads on different containers
 ## 1. Sequence Containers
-Sequence containers implement data structures which can be accessed sequentially.
+*Sequence containers* implement data structures which can be accessed sequentially.
 
 |name|description|
 |---|---|
@@ -12,18 +12,34 @@ Sequence containers implement data structures which can be accessed sequentially
 |forward_list|singly-linked list|
 |list|doubly-linked list|
 
+<br>
+
 ## 2. Unordered Containers
-Unordered associative containers implement unsorted (hashed) data structures that can be quickly searched (O(1) average, O(n) worst-case complexity).
+*Unordered associative containers* implement unsorted (hashed) data structures that can be quickly searched (**O(1) average, O(n) worst-case complexity**).
+
 |name|description|
 |---|---|
 |unordered_map|collection of key-value pairs, hashed by keys, keys are unique|
 |unordered_set|collection of unique keys, hashed by keys|
 
-## 3. Adapter Container
-**Container adaptors** provide a different interface for **sequential containers**.
+<br>
+
+## 3. Adapter Containers
+*Container adaptors* provide a different interface for **sequential containers**.
+
 |name|description|
 |---|---|
 |queue|apdapts a container to provide queue (**FIFO** data structure)|
 |stack|adapts a container to provide stack (**LIFO** data structure)|
 
-TBD
\ No newline at end of file
+<br>
+
+## 4. Associative Containers
+- *Associative containers* implement sorted data structures that can be quickly searched (**O(logn)**)
+
+|name|description|
+|---|---|
+|set|collection of unique keys, sorted by keys|
+|map|collection of key-value pairs, sorted by keys|
+
+<br>
diff --git a/src/core/datatypes/container/adapter/Queue.cpp b/src/core/datatypes/container/adapter/Queue.cpp
index da6fcbb..2cd91df 100644
--- a/src/core/datatypes/container/adapter/Queue.cpp
+++ b/src/core/datatypes/container/adapter/Queue.cpp
@@ -43,14 +43,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Queue : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "Queue"; }
   std::string description() const override { return "std::queue Example"; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Queue, "core", "Queue");
\ No newline at end of file
+REGISTER_EXAMPLE(Queue, "core/container", "Queue");
\ No newline at end of file
diff --git a/src/core/datatypes/container/adapter/Stack.cpp b/src/core/datatypes/container/adapter/Stack.cpp
index f40be12..3bc4c03 100644
--- a/src/core/datatypes/container/adapter/Stack.cpp
+++ b/src/core/datatypes/container/adapter/Stack.cpp
@@ -46,10 +46,10 @@ void run() {
 
 class Stack : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "Stack"; }
   std::string description() const override { return "std::stack Example"; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Stack, "core", "Stack");
\ No newline at end of file
+REGISTER_EXAMPLE(Stack, "core/container", "Stack");
\ No newline at end of file
diff --git a/src/core/datatypes/container/associative/Set.cpp b/src/core/datatypes/container/associative/Set.cpp
new file mode 100644
index 0000000..9cf3248
--- /dev/null
+++ b/src/core/datatypes/container/associative/Set.cpp
@@ -0,0 +1,33 @@
+
+// cppcheck-suppress-file []
+#include <iostream>
+#include <set>
+#include "ExampleRegistry.h"
+
+namespace {
+void run() {
+  // 1. Init
+  std::set<int> m_set{3, 4, 5, 1, 2};
+
+  // 2. Modifiers
+  m_set.insert(-1);
+
+  m_set.insert(99);
+  m_set.erase(99);
+
+  for (const auto k : m_set) {
+    std::cout << k << " ";
+  }
+  std::cout << std::endl;
+}
+}  // namespace
+
+class Set : public IExample {
+ public:
+  std::string group() const override { return "core/container"; }
+  std::string name() const override { return "Set"; }
+  std::string description() const override { return "std::set Example"; }
+  void execute() override { run(); }
+};
+
+REGISTER_EXAMPLE(Set, "core/container", "Set");
\ No newline at end of file
diff --git a/src/core/datatypes/container/sequence/Array.cpp b/src/core/datatypes/container/sequence/Array.cpp
index dd93c7e..64560ce 100644
--- a/src/core/datatypes/container/sequence/Array.cpp
+++ b/src/core/datatypes/container/sequence/Array.cpp
@@ -75,14 +75,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Array : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "Array"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Array, "core", "Array");
\ No newline at end of file
+REGISTER_EXAMPLE(Array, "core/container", "Array");
\ No newline at end of file
diff --git a/src/core/datatypes/container/sequence/Deque.cpp b/src/core/datatypes/container/sequence/Deque.cpp
index e9dc4cf..e161ea1 100644
--- a/src/core/datatypes/container/sequence/Deque.cpp
+++ b/src/core/datatypes/container/sequence/Deque.cpp
@@ -36,14 +36,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Deque : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "Deque"; }
   std::string description() const override { return "std::deque Example"; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Deque, "core", "Deque");
\ No newline at end of file
+REGISTER_EXAMPLE(Deque, "core/container", "Deque");
\ No newline at end of file
diff --git a/src/core/datatypes/container/sequence/Vector.cpp b/src/core/datatypes/container/sequence/Vector.cpp
index fc8c2b3..2286e8d 100644
--- a/src/core/datatypes/container/sequence/Vector.cpp
+++ b/src/core/datatypes/container/sequence/Vector.cpp
@@ -48,14 +48,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Vector : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "Vector"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Vector, "core", "Vector");
\ No newline at end of file
+REGISTER_EXAMPLE(Vector, "core/container", "Vector");
\ No newline at end of file
diff --git a/src/core/datatypes/container/unordered/UnorderedMap.cpp b/src/core/datatypes/container/unordered/UnorderedMap.cpp
index 855403a..fae0b00 100644
--- a/src/core/datatypes/container/unordered/UnorderedMap.cpp
+++ b/src/core/datatypes/container/unordered/UnorderedMap.cpp
@@ -70,14 +70,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class UnorderedMap : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/container"; }
   std::string name() const override { return "UnorderedMap"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(UnorderedMap, "core", "UnorderedMap");
\ No newline at end of file
+REGISTER_EXAMPLE(UnorderedMap, "core/container", "UnorderedMap");
\ No newline at end of file
diff --git a/src/core/datatypes/smart_pointer/Shared.cpp b/src/core/datatypes/smart_pointer/Shared.cpp
index 6af1d4a..48dc723 100644
--- a/src/core/datatypes/smart_pointer/Shared.cpp
+++ b/src/core/datatypes/smart_pointer/Shared.cpp
@@ -66,7 +66,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Shared : public IExample {
  public:
diff --git a/src/core/datatypes/smart_pointer/Unique.cpp b/src/core/datatypes/smart_pointer/Unique.cpp
index 6ec9179..514b6b6 100644
--- a/src/core/datatypes/smart_pointer/Unique.cpp
+++ b/src/core/datatypes/smart_pointer/Unique.cpp
@@ -54,7 +54,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Unique : public IExample {
  public:
diff --git a/src/core/datatypes/smart_pointer/Weak.cpp b/src/core/datatypes/smart_pointer/Weak.cpp
index 6980aec..3204bed 100644
--- a/src/core/datatypes/smart_pointer/Weak.cpp
+++ b/src/core/datatypes/smart_pointer/Weak.cpp
@@ -47,7 +47,6 @@ void run() {
  * wp.lock() != nullptr  // same condition
  */
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Weak : public IExample {
  public:
diff --git a/src/core/exception/BasicHandle.cpp b/src/core/exception/BasicHandle.cpp
index ee6746a..af5f026 100644
--- a/src/core/exception/BasicHandle.cpp
+++ b/src/core/exception/BasicHandle.cpp
@@ -24,11 +24,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class BasicHandle : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/exception"; }
   std::string name() const override { return "BasicHandle"; }
   std::string description() const override {
     return "Basic Expception Handle Example";
@@ -36,4 +35,4 @@ class BasicHandle : public IExample {
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(BasicHandle, "core", "BasicHandle");
\ No newline at end of file
+REGISTER_EXAMPLE(BasicHandle, "core/exception", "BasicHandle");
\ No newline at end of file
diff --git a/src/core/exception/ThrowNoexcept.cpp b/src/core/exception/ThrowNoexcept.cpp
index ee3315e..9be8f45 100644
--- a/src/core/exception/ThrowNoexcept.cpp
+++ b/src/core/exception/ThrowNoexcept.cpp
@@ -35,11 +35,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class ThrowNoexcept : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/exception"; }
   std::string name() const override { return "ThrowNoexcept"; }
   std::string description() const override {
     return "Exception throw/noexcept Example";
@@ -47,4 +46,4 @@ class ThrowNoexcept : public IExample {
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(ThrowNoexcept, "core", "ThrowNoexcept");
\ No newline at end of file
+REGISTER_EXAMPLE(ThrowNoexcept, "core/exception", "ThrowNoexcept");
\ No newline at end of file
diff --git a/src/core/expression/FunctionPointer.cpp b/src/core/expression/FunctionPointer.cpp
index 388b05f..04cdfb2 100644
--- a/src/core/expression/FunctionPointer.cpp
+++ b/src/core/expression/FunctionPointer.cpp
@@ -50,11 +50,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class FunctionPointer : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/expression"; }
   std::string name() const override { return "FunctionPointer"; }
   std::string description() const override {
     return "Function Pointer Example";
@@ -62,4 +61,4 @@ class FunctionPointer : public IExample {
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(FunctionPointer, "core", "FunctionPointer");
+REGISTER_EXAMPLE(FunctionPointer, "core/expression", "FunctionPointer");
diff --git a/src/core/expression/Lambda.cpp b/src/core/expression/Lambda.cpp
index 58bdb56..b93a7f1 100644
--- a/src/core/expression/Lambda.cpp
+++ b/src/core/expression/Lambda.cpp
@@ -37,11 +37,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Lambda : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/expression"; }
   std::string name() const override { return "Lambda"; }
   std::string description() const override {
     return "Lambda Expression Example";
@@ -49,4 +48,4 @@ class Lambda : public IExample {
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Lambda, "core", "Lambda");
+REGISTER_EXAMPLE(Lambda, "core/expression", "Lambda");
diff --git a/src/core/filehandle/Directory.cpp b/src/core/filehandle/Directory.cpp
index 08365f7..bb62f77 100644
--- a/src/core/filehandle/Directory.cpp
+++ b/src/core/filehandle/Directory.cpp
@@ -3,7 +3,6 @@
 #include <string>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 void run() {
@@ -44,10 +43,10 @@ void run() {
 
 class Directory : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/filehandle"; }
   std::string name() const override { return "Directory"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(Directory, "core", "Directory");
\ No newline at end of file
+REGISTER_EXAMPLE(Directory, "core/filehandle", "Directory");
\ No newline at end of file
diff --git a/src/core/filehandle/FileIO.cpp b/src/core/filehandle/FileIO.cpp
index 8de57dd..bfd505f 100644
--- a/src/core/filehandle/FileIO.cpp
+++ b/src/core/filehandle/FileIO.cpp
@@ -107,14 +107,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class FileIO : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/filehandle"; }
   std::string name() const override { return "FileIO"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(FileIO, "core", "FileIO");
\ No newline at end of file
+REGISTER_EXAMPLE(FileIO, "core/filehandle", "FileIO");
\ No newline at end of file
diff --git a/src/core/filehandle/IOStream.cpp b/src/core/filehandle/IOStream.cpp
index 0a93afe..a8e78c8 100644
--- a/src/core/filehandle/IOStream.cpp
+++ b/src/core/filehandle/IOStream.cpp
@@ -3,7 +3,6 @@
 #include <string>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 void run() {
@@ -33,10 +32,10 @@ void run() {
 
 class IOStream : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/filehandle"; }
   std::string name() const override { return "IOStream"; }
   std::string description() const override { return ""; }
   void execute() override { run(); }
 };
 
-REGISTER_EXAMPLE(IOStream, "core", "IOStream");
\ No newline at end of file
+REGISTER_EXAMPLE(IOStream, "core/filehandle", "IOStream");
\ No newline at end of file
diff --git a/src/core/filehandle/StringStream.cpp b/src/core/filehandle/StringStream.cpp
index e77b261..9185084 100644
--- a/src/core/filehandle/StringStream.cpp
+++ b/src/core/filehandle/StringStream.cpp
@@ -3,7 +3,6 @@
 #include <string>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 void runStringStreamExample() {
@@ -40,10 +39,10 @@ void runStringStreamExample() {
 
 class StringStream : public IExample {
  public:
-  std::string group() const override { return "core"; }
+  std::string group() const override { return "core/filehandle"; }
   std::string name() const override { return "StringStream"; }
   std::string description() const override { return ""; }
   void execute() override { runStringStreamExample(); }
 };
 
-REGISTER_EXAMPLE(StringStream, "core", "StringStream");
\ No newline at end of file
+REGISTER_EXAMPLE(StringStream, "core/filehandle", "StringStream");
\ No newline at end of file
diff --git a/src/core/linkage/Linkage.cpp b/src/core/linkage/Linkage.cpp
index 59ea4f4..2223ed4 100644
--- a/src/core/linkage/Linkage.cpp
+++ b/src/core/linkage/Linkage.cpp
@@ -39,7 +39,6 @@ void run() {
 }  // namespace External
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Linkage : public IExample {
  public:
diff --git a/src/core/linkage/sharing/Sharing.cpp b/src/core/linkage/sharing/Sharing.cpp
index 0e3d4e7..629232f 100644
--- a/src/core/linkage/sharing/Sharing.cpp
+++ b/src/core/linkage/sharing/Sharing.cpp
@@ -25,7 +25,6 @@ void run() {
 }  // namespace InlineWay
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class Sharing : public IExample {
  public:
diff --git a/src/core/string/CString.cpp b/src/core/string/CString.cpp
index 56d7029..d5e83b0 100644
--- a/src/core/string/CString.cpp
+++ b/src/core/string/CString.cpp
@@ -192,7 +192,6 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CString : public IExample {
  public:
diff --git a/src/main.cpp b/src/main.cpp
index 199bc1d..ad8b908 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -37,16 +37,21 @@ void runMenu() {
     std::vector<std::string> groups;
 
     for (const auto& [group, _] : data) {
-      std::cout << gIndex++ << ". " << group << "\n";
       groups.push_back(group);
     }
-    std::cout << "0. quit\n";
+
+    // sort
+    std::sort(groups.begin(), groups.end());
+    for (const auto& group : groups) {
+      std::cout << gIndex++ << ". " << group << "\n";
+    }
+    std::cout << "0. Exit\n";
     std::cout << "----------------------------------------\n";
     std::cout << "Enter choice: ";
 
     int gChoice = readChoice();
     if (gChoice == 0) {
-      std::cout << "End\n";
+      std::cout << "\n--- Exit ---\n";
       break;
     }
 
@@ -67,7 +72,7 @@ void runMenu() {
         std::cout << eIndex++ << ". " << name << "\n";
         names.push_back(name);
       }
-      std::cout << "0. back\n";
+      std::cout << "0. Back\n";
       std::cout << "----------------------------------------\n";
       std::cout << "Enter choice: ";
 
diff --git a/src/patterns/behavioral/ChainOfCommand.cpp b/src/patterns/behavioral/ChainOfCommand.cpp
index a359d61..fca6de1 100644
--- a/src/patterns/behavioral/ChainOfCommand.cpp
+++ b/src/patterns/behavioral/ChainOfCommand.cpp
@@ -135,15 +135,14 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class ChainOfResponsibilityExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "ChainOfResponsibility"; }
   std::string description() const override { return "CoR Pattern Example"; }
   void execute() override { CoR::run(); }
 };
 
-REGISTER_EXAMPLE(ChainOfResponsibilityExample, "patterns",
+REGISTER_EXAMPLE(ChainOfResponsibilityExample, "patterns/behavioral",
                  "ChainOfResponsibility");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Command.cpp b/src/patterns/behavioral/Command.cpp
index dc73396..240c4b7 100644
--- a/src/patterns/behavioral/Command.cpp
+++ b/src/patterns/behavioral/Command.cpp
@@ -126,14 +126,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CommandExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Command"; }
   std::string description() const override { return "Command Pattern Example"; }
   void execute() override { Command::run(); }
 };
 
-REGISTER_EXAMPLE(CommandExample, "patterns", "Command");
\ No newline at end of file
+REGISTER_EXAMPLE(CommandExample, "patterns/behavioral", "Command");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Iterator.cpp b/src/patterns/behavioral/Iterator.cpp
index 0222e69..cd085f7 100644
--- a/src/patterns/behavioral/Iterator.cpp
+++ b/src/patterns/behavioral/Iterator.cpp
@@ -197,11 +197,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class IteratorExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Iterator"; }
   std::string description() const override {
     return "Iterator Pattern Example";
@@ -209,4 +208,4 @@ class IteratorExample : public IExample {
   void execute() override { Iterator::run(); }
 };
 
-REGISTER_EXAMPLE(IteratorExample, "patterns", "Iterator");
\ No newline at end of file
+REGISTER_EXAMPLE(IteratorExample, "patterns/behavioral", "Iterator");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Mediator.cpp b/src/patterns/behavioral/Mediator.cpp
index ec28195..1bb8e96 100644
--- a/src/patterns/behavioral/Mediator.cpp
+++ b/src/patterns/behavioral/Mediator.cpp
@@ -163,11 +163,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class MediatorExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Mediator"; }
   std::string description() const override {
     return "Mediator Pattern Example";
@@ -175,4 +174,4 @@ class MediatorExample : public IExample {
   void execute() override { Mediator::run(); }
 };
 
-REGISTER_EXAMPLE(MediatorExample, "patterns", "Mediator");
\ No newline at end of file
+REGISTER_EXAMPLE(MediatorExample, "patterns/behavioral", "Mediator");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Memento.cpp b/src/patterns/behavioral/Memento.cpp
index 6f378c2..0eedf6e 100644
--- a/src/patterns/behavioral/Memento.cpp
+++ b/src/patterns/behavioral/Memento.cpp
@@ -192,11 +192,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class MementoExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Memento"; }
   std::string description() const override {
     return "Memento Pattern Example ";
@@ -204,4 +203,4 @@ class MementoExample : public IExample {
   void execute() override { Memento::run(); }
 };
 
-REGISTER_EXAMPLE(MementoExample, "patterns", "Memento");
\ No newline at end of file
+REGISTER_EXAMPLE(MementoExample, "patterns/behavioral", "Memento");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Observer.cpp b/src/patterns/behavioral/Observer.cpp
index cf8a62f..decb5e5 100644
--- a/src/patterns/behavioral/Observer.cpp
+++ b/src/patterns/behavioral/Observer.cpp
@@ -176,11 +176,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class ObserverExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Observer"; }
   std::string description() const override {
     return "Observer Pattern Example";
@@ -188,4 +187,4 @@ class ObserverExample : public IExample {
   void execute() override { Observer::run(); }
 };
 
-REGISTER_EXAMPLE(ObserverExample, "patterns", "Observer");
\ No newline at end of file
+REGISTER_EXAMPLE(ObserverExample, "patterns/behavioral", "Observer");
\ No newline at end of file
diff --git a/src/patterns/behavioral/State.cpp b/src/patterns/behavioral/State.cpp
index a507cd5..05fb9a5 100644
--- a/src/patterns/behavioral/State.cpp
+++ b/src/patterns/behavioral/State.cpp
@@ -133,14 +133,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class StateExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "State"; }
   std::string description() const override { return "State Pattern Example"; }
   void execute() override { State::run(); }
 };
 
-REGISTER_EXAMPLE(StateExample, "patterns", "State");
\ No newline at end of file
+REGISTER_EXAMPLE(StateExample, "patterns/behavioral", "State");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Strategy.cpp b/src/patterns/behavioral/Strategy.cpp
index e9b7084..a929389 100644
--- a/src/patterns/behavioral/Strategy.cpp
+++ b/src/patterns/behavioral/Strategy.cpp
@@ -102,11 +102,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class StrategyExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Strategy"; }
   std::string description() const override {
     return "Strategy Pattern Example";
@@ -114,4 +113,4 @@ class StrategyExample : public IExample {
   void execute() override { Strategy::run(); }
 };
 
-REGISTER_EXAMPLE(StrategyExample, "patterns", "Strategy");
\ No newline at end of file
+REGISTER_EXAMPLE(StrategyExample, "patterns/behavioral", "Strategy");
\ No newline at end of file
diff --git a/src/patterns/behavioral/TemplateMethod.cpp b/src/patterns/behavioral/TemplateMethod.cpp
index 5ce9852..0cdcdf6 100644
--- a/src/patterns/behavioral/TemplateMethod.cpp
+++ b/src/patterns/behavioral/TemplateMethod.cpp
@@ -104,11 +104,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class TemplateMethodExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "TemplateMethod"; }
   std::string description() const override {
     return "TemplateMethod Pattern Example";
@@ -116,4 +115,4 @@ class TemplateMethodExample : public IExample {
   void execute() override { TemplateMethod::run(); }
 };
 
-REGISTER_EXAMPLE(TemplateMethodExample, "patterns", "TemplateMethod");
\ No newline at end of file
+REGISTER_EXAMPLE(TemplateMethodExample, "patterns/behavioral", "TemplateMethod");
\ No newline at end of file
diff --git a/src/patterns/behavioral/Visitor.cpp b/src/patterns/behavioral/Visitor.cpp
index 54aff44..ea11a59 100644
--- a/src/patterns/behavioral/Visitor.cpp
+++ b/src/patterns/behavioral/Visitor.cpp
@@ -237,14 +237,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class VisitorExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/behavioral"; }
   std::string name() const override { return "Visitor"; }
   std::string description() const override { return "Visitor Pattern Example"; }
   void execute() override { Visitor::run(); }
 };
 
-REGISTER_EXAMPLE(VisitorExample, "patterns", "Visitor");
\ No newline at end of file
+REGISTER_EXAMPLE(VisitorExample, "patterns/behavioral", "Visitor");
\ No newline at end of file
diff --git a/src/patterns/creational/AbstractFactory.cpp b/src/patterns/creational/AbstractFactory.cpp
index 8b3b10e..b78653a 100644
--- a/src/patterns/creational/AbstractFactory.cpp
+++ b/src/patterns/creational/AbstractFactory.cpp
@@ -164,11 +164,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class AbstractFactoryExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/creational"; }
   std::string name() const override { return "AbstractFactory"; }
   std::string description() const override {
     return "AbstractFactory Pattern Example";
@@ -176,4 +175,4 @@ class AbstractFactoryExample : public IExample {
   void execute() override { AbstractFactory::run(); }
 };
 
-REGISTER_EXAMPLE(AbstractFactoryExample, "patterns", "AbstractFactory");
\ No newline at end of file
+REGISTER_EXAMPLE(AbstractFactoryExample, "patterns/creational", "AbstractFactory");
\ No newline at end of file
diff --git a/src/patterns/creational/Builder.cpp b/src/patterns/creational/Builder.cpp
index 5c32374..46ed44f 100644
--- a/src/patterns/creational/Builder.cpp
+++ b/src/patterns/creational/Builder.cpp
@@ -162,14 +162,13 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class BuilderExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/creational"; }
   std::string name() const override { return "Builder"; }
   std::string description() const override { return "Builder Pattern Example"; }
   void execute() override { BuilderPattern::run(); }
 };
 
-REGISTER_EXAMPLE(BuilderExample, "patterns", "Builder");
\ No newline at end of file
+REGISTER_EXAMPLE(BuilderExample, "patterns/creational", "Builder");
\ No newline at end of file
diff --git a/src/patterns/creational/FactoryMethod.cpp b/src/patterns/creational/FactoryMethod.cpp
index 78962b4..80dc69f 100644
--- a/src/patterns/creational/FactoryMethod.cpp
+++ b/src/patterns/creational/FactoryMethod.cpp
@@ -131,11 +131,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class FactoryMethodExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/creational"; }
   std::string name() const override { return "FactoryMethod"; }
   std::string description() const override {
     return "FactoryMethod Pattern Example";
@@ -143,4 +142,4 @@ class FactoryMethodExample : public IExample {
   void execute() override { FactoryMethod::run(); }
 };
 
-REGISTER_EXAMPLE(FactoryMethodExample, "patterns", "FactoryMethod");
\ No newline at end of file
+REGISTER_EXAMPLE(FactoryMethodExample, "patterns/creational", "FactoryMethod");
\ No newline at end of file
diff --git a/src/patterns/creational/Prototype.cpp b/src/patterns/creational/Prototype.cpp
index 1ec8a0a..8fd289c 100644
--- a/src/patterns/creational/Prototype.cpp
+++ b/src/patterns/creational/Prototype.cpp
@@ -118,11 +118,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class PrototypeExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/creational"; }
   std::string name() const override { return "Prototype"; }
   std::string description() const override {
     return "Prototype Pattern Example";
@@ -130,4 +129,4 @@ class PrototypeExample : public IExample {
   void execute() override { Prototy::run(); }
 };
 
-REGISTER_EXAMPLE(PrototypeExample, "patterns", "Prototype");
\ No newline at end of file
+REGISTER_EXAMPLE(PrototypeExample, "patterns/creational", "Prototype");
\ No newline at end of file
diff --git a/src/patterns/creational/Singleton.cpp b/src/patterns/creational/Singleton.cpp
index 953e629..65e845e 100644
--- a/src/patterns/creational/Singleton.cpp
+++ b/src/patterns/creational/Singleton.cpp
@@ -71,11 +71,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class SingletonExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/creational"; }
   std::string name() const override { return "Singleton"; }
   std::string description() const override {
     return "Singleton Pattern Example";
@@ -83,4 +82,4 @@ class SingletonExample : public IExample {
   void execute() override { SingletonPattern::run(); }
 };
 
-REGISTER_EXAMPLE(SingletonExample, "patterns", "Singleton");
\ No newline at end of file
+REGISTER_EXAMPLE(SingletonExample, "patterns/creational", "Singleton");
\ No newline at end of file
diff --git a/src/patterns/structural/Adapter.cpp b/src/patterns/structural/Adapter.cpp
index 98e35ee..90fcead 100644
--- a/src/patterns/structural/Adapter.cpp
+++ b/src/patterns/structural/Adapter.cpp
@@ -142,11 +142,10 @@ void run() {
 }  // namespace CaseStudy
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class AdapterExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Adapter"; }
   std::string description() const override { return "Factory Pattern Example"; }
   void execute() override {
@@ -155,4 +154,4 @@ class AdapterExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(AdapterExample, "patterns", "Adapter");
\ No newline at end of file
+REGISTER_EXAMPLE(AdapterExample, "patterns/structural", "Adapter");
\ No newline at end of file
diff --git a/src/patterns/structural/Bridge.cpp b/src/patterns/structural/Bridge.cpp
index 234bfb0..f6a19a9 100644
--- a/src/patterns/structural/Bridge.cpp
+++ b/src/patterns/structural/Bridge.cpp
@@ -14,7 +14,6 @@
 #include <iostream>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 namespace Problem {
@@ -172,7 +171,7 @@ void run() {
 
 class BridgeExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Bridge"; }
   std::string description() const override { return "Bridge Pattern Example"; }
   void execute() override {
@@ -181,5 +180,5 @@ class BridgeExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(BridgeExample, "patterns", "Bridge");
+REGISTER_EXAMPLE(BridgeExample, "patterns/structural", "Bridge");
 }  // namespace
\ No newline at end of file
diff --git a/src/patterns/structural/Composite.cpp b/src/patterns/structural/Composite.cpp
index 968bbc2..7a40213 100644
--- a/src/patterns/structural/Composite.cpp
+++ b/src/patterns/structural/Composite.cpp
@@ -426,11 +426,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class CompositeExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Composite"; }
   std::string description() const override {
     return "Composite Pattern Example";
@@ -441,4 +440,4 @@ class CompositeExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(CompositeExample, "patterns", "Composite");
\ No newline at end of file
+REGISTER_EXAMPLE(CompositeExample, "patterns/structural", "Composite");
\ No newline at end of file
diff --git a/src/patterns/structural/Decorator.cpp b/src/patterns/structural/Decorator.cpp
index 20e8b61..5e66230 100644
--- a/src/patterns/structural/Decorator.cpp
+++ b/src/patterns/structural/Decorator.cpp
@@ -186,11 +186,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class DecoratorExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Decorator"; }
   std::string description() const override {
     return "Decorator Pattern Example";
@@ -201,4 +200,4 @@ class DecoratorExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(DecoratorExample, "patterns", "Decorator");
\ No newline at end of file
+REGISTER_EXAMPLE(DecoratorExample, "patterns/structural", "Decorator");
\ No newline at end of file
diff --git a/src/patterns/structural/Facade.cpp b/src/patterns/structural/Facade.cpp
index 4fc7f54..04f8940 100644
--- a/src/patterns/structural/Facade.cpp
+++ b/src/patterns/structural/Facade.cpp
@@ -210,11 +210,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class FacadeExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Facade"; }
   std::string description() const override { return "Facade Pattern Example"; }
   void execute() override {
@@ -223,4 +222,4 @@ class FacadeExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(FacadeExample, "patterns", "Facade");
\ No newline at end of file
+REGISTER_EXAMPLE(FacadeExample, "patterns/structural", "Facade");
\ No newline at end of file
diff --git a/src/patterns/structural/Flyweight.cpp b/src/patterns/structural/Flyweight.cpp
index 61aa2ad..ed9436d 100644
--- a/src/patterns/structural/Flyweight.cpp
+++ b/src/patterns/structural/Flyweight.cpp
@@ -328,11 +328,10 @@ void run() {
 }  // namespace
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 class FlyweightExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Flyweight"; }
   std::string description() const override {
     return "Flyweight Pattern Example";
@@ -343,4 +342,4 @@ class FlyweightExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(FlyweightExample, "patterns", "Flyweight");
\ No newline at end of file
+REGISTER_EXAMPLE(FlyweightExample, "patterns/structural", "Flyweight");
\ No newline at end of file
diff --git a/src/patterns/structural/Proxy.cpp b/src/patterns/structural/Proxy.cpp
index 0589aff..a5d79f8 100644
--- a/src/patterns/structural/Proxy.cpp
+++ b/src/patterns/structural/Proxy.cpp
@@ -17,7 +17,6 @@
 #include <iostream>
 
 #include "ExampleRegistry.h"
-#include "IExample.h"
 
 namespace {
 namespace Problem {
@@ -222,7 +221,7 @@ void run() {
 
 class ProxyExample : public IExample {
  public:
-  std::string group() const override { return "patterns"; }
+  std::string group() const override { return "patterns/structural"; }
   std::string name() const override { return "Proxy"; }
   std::string description() const override { return "Proxy Pattern Example"; }
   void execute() override {
@@ -231,5 +230,5 @@ class ProxyExample : public IExample {
   }
 };
 
-REGISTER_EXAMPLE(ProxyExample, "patterns", "Proxy");
+REGISTER_EXAMPLE(ProxyExample, "patterns/structural", "Proxy");
 }  // namespace