diff --git a/.gitignore b/.gitignore
index fe260c7..198a84e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /.cache/
 /devbox.lock
 /subprojects/cpputest-4.0/
+/subprojects/packagecache/
diff --git a/devbox.json b/devbox.json
new file mode 100644
index 0000000..da4a8ef
--- /dev/null
+++ b/devbox.json
@@ -0,0 +1,12 @@
+{
+  "$schema": "https://raw.githubusercontent.com/jetify-com/devbox/0.12.0/.schema/devbox.schema.json",
+  "packages": [
+    "meson@latest",
+    "gcc14@latest"
+  ],
+  "shell": {
+    "init_hook": [
+      "echo 'Welcome to the DSA Learning Zone!' > /dev/null"
+    ],
+  }
+}
diff --git a/libs/chapter1/chapter1.hpp b/libs/chapter1/chapter1.hpp
new file mode 100644
index 0000000..ccc57c4
--- /dev/null
+++ b/libs/chapter1/chapter1.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <stdlib.h>
+
+bool IsUnique(const char* s, int len);
+bool CheckPermutation(const char* s1, const char* s2, size_t s1_len, size_t s2_len);
diff --git a/libs/chapter1/check_permutation.cpp b/libs/chapter1/check_permutation.cpp
new file mode 100644
index 0000000..720832b
--- /dev/null
+++ b/libs/chapter1/check_permutation.cpp
@@ -0,0 +1,35 @@
+#include <iostream>
+#include <string>
+#include "chapter1.hpp"
+
+/* Prompt
+   Check Permutation: Given two strings, write a method to decide if
+   one is a permutation of the other.
+ */
+
+bool CheckPermutation(const char* s1, const char* s2,
+                      size_t s1_len, size_t s2_len){
+
+  int letters1[255] = {};
+  int letters2[255] = {};
+  long unsigned int indx = 0;
+
+  if(s1_len != s2_len){
+    return false;
+  }
+
+  for(indx = 0; indx < s1_len; ++indx){
+    int li1 = static_cast<int>(s1[indx]);
+    int li2 = static_cast<int>(s2[indx]);
+    letters1[li1] += 1;
+    letters2[li2] += 1;
+  }
+
+  for(indx = 0; indx < 255; ++indx){
+    if (letters1[indx] != letters2[indx]){
+      return false;
+    }
+  }
+
+  return true;
+}
diff --git a/libs/chapter1/is_unique.cpp b/libs/chapter1/is_unique.cpp
new file mode 100644
index 0000000..108d8ab
--- /dev/null
+++ b/libs/chapter1/is_unique.cpp
@@ -0,0 +1,21 @@
+#include <iostream>
+#include "chapter1.hpp"
+
+/* Prompt
+   Is Unique: Implement an algorithm to determine if a string
+   has all unique characters. What if you cannot use additional data
+   structures?
+*/
+
+bool IsUnique(const char* s, int len){
+  int tracker[255]= {};
+
+  for(int i=0; i<len; ++i){
+    int tracker_index = static_cast<int>(s[i]);
+    tracker[tracker_index] += 1;
+    if (tracker[tracker_index] > 1){
+      return false;
+    }
+  }
+  return true;
+}
diff --git a/libs/chapter1/meson.build b/libs/chapter1/meson.build
new file mode 100644
index 0000000..490a549
--- /dev/null
+++ b/libs/chapter1/meson.build
@@ -0,0 +1,5 @@
+
+chapter1_sources = ['is_unique.cpp', 'check_permutation.cpp']
+
+chapter1_lib = static_library('chapter1',
+                              chapter1_sources)
diff --git a/libs/chapter12/chapter12.hpp b/libs/chapter12/chapter12.hpp
new file mode 100644
index 0000000..592c3f5
--- /dev/null
+++ b/libs/chapter12/chapter12.hpp
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <iostream>
+
+void reverse_str(char* str);
diff --git a/libs/chapter12/meson.build b/libs/chapter12/meson.build
new file mode 100644
index 0000000..4fcfff0
--- /dev/null
+++ b/libs/chapter12/meson.build
@@ -0,0 +1,4 @@
+chapter12_sources = ['reverse_string.cpp']
+
+chapter12_lib = static_library('chapter12',
+                               chapter12_sources)
diff --git a/libs/chapter12/reverse_string.cpp b/libs/chapter12/reverse_string.cpp
new file mode 100644
index 0000000..c6dc7e1
--- /dev/null
+++ b/libs/chapter12/reverse_string.cpp
@@ -0,0 +1,20 @@
+#include "chapter12.hpp"
+#include <string.h>
+#include <stdlib.h>
+
+/*
+  Reverse String: Implement a function void reverse( char* str) in C or C++ which reverses
+  a null-terminated string.
+*/
+
+void reverse_str(char *str){
+  size_t len = strlen(str);
+  char *tmp = reinterpret_cast<char*>(malloc(len));
+  strcpy(tmp, str);
+  for(unsigned int offset = 0; offset < len; ++offset){
+    str[offset] = tmp[len-offset-1];
+  }
+  str[len] = '\0';
+
+  free(tmp);
+}
diff --git a/libs/chapter2/chapter2.hpp b/libs/chapter2/chapter2.hpp
new file mode 100644
index 0000000..b944255
--- /dev/null
+++ b/libs/chapter2/chapter2.hpp
@@ -0,0 +1,7 @@
+#pragma once
+
+#include <dope/linkedlist.hpp>
+
+// Utility functions
+void remove_dups(DopeLinkedList* ll);
+void reverse_linkedlist(DopeLinkedList* ll);
diff --git a/libs/chapter2/meson.build b/libs/chapter2/meson.build
new file mode 100644
index 0000000..ecdf910
--- /dev/null
+++ b/libs/chapter2/meson.build
@@ -0,0 +1,5 @@
+ch2_srcs = ['remove_dups.cpp', 'reverse.cpp']
+
+chapter2_lib = static_library('chapter2',
+                              ch2_srcs,
+                              include_directories: libs_includes)
diff --git a/libs/chapter2/remove_dups.cpp b/libs/chapter2/remove_dups.cpp
new file mode 100644
index 0000000..7a0623b
--- /dev/null
+++ b/libs/chapter2/remove_dups.cpp
@@ -0,0 +1,35 @@
+#include "chapter2.hpp"
+#include <unordered_map>
+
+/*
+Remove Dups!
+Write code to remove duplicates from an unsorted linked list.
+FOLLOW UP
+How would you solve this problem if a temporary buffer is not allowed?
+ */
+
+void remove_dups(DopeLinkedList* ll){
+  DopeNode* prev = ll->GetHead();
+  DopeNode* node = ll->GetHead();
+  DopeNode* tmp = NULL;
+  std::unordered_map<int, int> dup_tracker;
+  int iter_cnt = 0;
+
+  while(node->GetNext() != NULL){
+    if(dup_tracker.count(node->GetData())){
+      // remove node
+      prev->SetNext(node->GetNext());
+      tmp = node;
+      node = node->GetNext();
+      tmp->Reset();
+    } else {
+      dup_tracker[node->GetData()] += 1;
+      node = node->GetNext();
+      if (iter_cnt != 0){
+        prev = prev->GetNext();
+      }
+    }
+
+    iter_cnt++;
+  }
+}
diff --git a/libs/chapter2/reverse.cpp b/libs/chapter2/reverse.cpp
new file mode 100644
index 0000000..191789d
--- /dev/null
+++ b/libs/chapter2/reverse.cpp
@@ -0,0 +1,32 @@
+#include "chapter2.hpp"
+#include <stack>
+
+/*
+Reverse Linked List
+ */
+
+void reverse_linkedlist(DopeLinkedList* ll){
+  DopeNode* node = ll->GetHead();
+  DopeNode* prev = nullptr;
+  std::stack<DopeNode*> s;
+  int iter_cnt = 0;
+  s.push(node);
+  while(node->GetNext() != NULL){
+    s.push(node);
+    node = node->GetNext();
+    iter_cnt++;
+  }
+  s.push(node);
+
+  prev = s.top();
+  s.pop();
+  ll->SetHead(prev);
+  while(!s.empty()){
+    node = s.top();
+    s.pop();
+    prev->SetNext(node);
+    prev = node;
+  }
+  node->SetNext(nullptr);
+
+}
diff --git a/libs/dope/bintree.hpp b/libs/dope/bintree.hpp
new file mode 100644
index 0000000..b521e41
--- /dev/null
+++ b/libs/dope/bintree.hpp
@@ -0,0 +1,172 @@
+#pragma once
+
+#include <queue>
+
+template <class T>
+class DopeBinTreeNode{
+  DopeBinTreeNode<T>* left;
+  DopeBinTreeNode<T>* right;
+  T data;
+public:
+  DopeBinTreeNode(T data);
+  ~DopeBinTreeNode();
+  void SetLeft(DopeBinTreeNode<T>* newleft){left = newleft;}
+  void SetRight(DopeBinTreeNode<T>* newright){right = newright;}
+  DopeBinTreeNode<T>* GetLeft(){return left;}
+  DopeBinTreeNode<T>* GetRight(){return right;}
+  T GetData(){return data;}
+};
+
+template <class T>
+class DopeBinTree{
+  DopeBinTreeNode<T>* root;
+  T* RecPreOrderTraversal(DopeBinTreeNode<T>* node, T* out);
+  T* RecInOrderTraversal(DopeBinTreeNode<T>* node, T* out);
+  T* RecPostOrderTraversal(DopeBinTreeNode<T>* node, T* out);
+public:
+  DopeBinTree(T data);
+  DopeBinTree();
+  ~DopeBinTree();
+  void insert(T data);
+  bool isEmpty();
+  DopeBinTreeNode<T>* getRoot(){return root;}
+  void RecPreOrderTraversalArray(T* array);
+  void RecInOrderTraversalArray(T* array);
+  void RecPostOrderTraversalArray(T* array);
+};
+
+// Implementations ___________________________________________________
+template <class T>
+DopeBinTreeNode<T>::DopeBinTreeNode(T node_data):
+  left(nullptr),
+  right(nullptr),
+  data(node_data)
+{
+
+}
+template <class T>
+DopeBinTreeNode<T>::~DopeBinTreeNode(){
+  delete left;
+  delete right;
+}
+
+template <class T>
+DopeBinTree<T>::DopeBinTree(T data){
+  root = new DopeBinTreeNode<T>(data);
+}
+
+template <class T>
+DopeBinTree<T>::DopeBinTree():
+  root(nullptr)
+{
+
+}
+
+template <class T>
+DopeBinTree<T>::~DopeBinTree(){
+  if (root != nullptr){
+    delete root;
+  }
+
+}
+
+template <class T>
+// Insert Breadth first
+void DopeBinTree<T>::insert(T data){
+  DopeBinTreeNode<T>* current_node = root;
+  if (root == nullptr){
+    root = new DopeBinTreeNode<T>(data);
+  } else {
+    auto new_node = new DopeBinTreeNode<T>(data);
+    // Breadth first traversal
+    std::queue<DopeBinTreeNode<T>*> q;
+    q.push(root);
+    while(!q.empty()){
+      current_node = q.front();
+      q.pop();
+      if(current_node->GetLeft()){
+        q.push(current_node->GetLeft());
+      } else {
+        current_node->SetLeft(new_node);
+        break;
+      }
+      if(current_node->GetRight()){
+        q.push(current_node->GetRight());
+      } else {
+        current_node->SetRight(new_node);
+        break;
+      }
+    }
+  }
+}
+
+template <class T>
+bool DopeBinTree<T>::isEmpty(){
+  if(root == nullptr){
+    return true;
+  } else {
+    return false;
+  }
+}
+
+template <class T>
+T* DopeBinTree<T>::RecPreOrderTraversal(DopeBinTreeNode<T>* node, T* out){
+  if (node == nullptr){
+    return out--;
+  }
+  *out = node->GetData();
+  out++;
+  out = RecPreOrderTraversal(node->GetLeft(), out);
+  out = RecPreOrderTraversal(node->GetRight(), out);
+  return out;
+}
+
+template <class T>
+T* DopeBinTree<T>::RecInOrderTraversal(DopeBinTreeNode<T>* node, T* out){
+  if (node == nullptr){
+    return out--;
+  }
+
+  out = RecInOrderTraversal(node->GetLeft(), out);
+  *out = node->GetData();
+  out++;
+  out = RecInOrderTraversal(node->GetRight(), out);
+  return out;
+}
+
+template <class T>
+T* DopeBinTree<T>::RecPostOrderTraversal(DopeBinTreeNode<T>* node, T* out){
+  if (node == nullptr){
+    return out--;
+  }
+  out = RecPostOrderTraversal(node->GetLeft(), out);
+  out = RecPostOrderTraversal(node->GetRight(), out);
+  *out = node->GetData();
+  out++;
+  return out;
+}
+
+template <class T>
+void DopeBinTree<T>::RecPreOrderTraversalArray(T* array){
+  int index = 0;
+  DopeBinTreeNode<T>* node = root;
+
+  RecPreOrderTraversal(node, &array[index]);
+
+}
+
+template <class T>
+void DopeBinTree<T>::RecInOrderTraversalArray(T* array){
+  int index = 0;
+  DopeBinTreeNode<T>* node = root;
+
+  RecInOrderTraversal(node, &array[index]);
+}
+
+template <class T>
+void DopeBinTree<T>::RecPostOrderTraversalArray(T* array){
+  int index = 0;
+  DopeBinTreeNode<T>* node = root;
+
+  RecPostOrderTraversal(node, &array[index]);
+}
diff --git a/libs/dope/linkedlist.cpp b/libs/dope/linkedlist.cpp
new file mode 100644
index 0000000..92fc4be
--- /dev/null
+++ b/libs/dope/linkedlist.cpp
@@ -0,0 +1,56 @@
+#include "linkedlist.hpp"
+
+DopeLinkedList::DopeLinkedList(){
+  for(int i = 0; i < MAX_DOPE_NODES; ++i){
+    nodes[i].Reset();
+  }
+  head = &nodes[0];
+}
+
+DopeNode::DopeNode(int init_data){
+  data = init_data;
+  next = NULL;
+  state = NodeState::UnInitialized;
+}
+
+DopeNode::DopeNode(){
+  Reset();
+}
+
+void DopeNode::Reset(){
+  this->data = 0;
+  this->next = NULL;
+  this->state = NodeState::UnInitialized;
+}
+
+void DopeLinkedList::AppendData(int init_data){
+  DopeNode* new_node = head;
+  DopeNode* node = head;
+  // Find next free slot and allocate it for the new node
+  for(int i=0; i < MAX_DOPE_NODES; ++i){
+    if(nodes[i].GetState() == NodeState::UnInitialized){
+      new_node = &nodes[i];
+      new_node->SetNext(NULL);
+      new_node->SetState(NodeState::Initialized);
+      new_node->SetData(init_data);
+      break;
+    }
+  }
+
+  if(head == new_node){
+    // Just set first node, nothing else to do
+    return;
+  }
+
+  // Find last node in linked list
+  if ((head->GetNext() == NULL) && (head->GetState() == NodeState::Initialized)){
+    // Special case, only one node so far
+    head->SetNext(new_node);
+  } else {
+    while(node->GetNext() != NULL){
+      node = node->GetNext();
+    }
+    node->SetNext(new_node);
+  }
+
+}
diff --git a/libs/dope/linkedlist.hpp b/libs/dope/linkedlist.hpp
new file mode 100644
index 0000000..5584bf1
--- /dev/null
+++ b/libs/dope/linkedlist.hpp
@@ -0,0 +1,37 @@
+#pragma once
+
+#include<stdlib.h>
+
+#define MAX_DOPE_NODES 255
+
+typedef enum NodeState_E{
+  UnInitialized,
+  Initialized
+} NodeState;
+
+class DopeNode {
+  int data;
+  DopeNode* next;
+  NodeState state;
+public:
+  DopeNode(int data);
+  DopeNode();
+  DopeNode* GetNext(){return next;}
+  NodeState GetState(){return state;}
+  int GetData(){return data;}
+  void SetNext(DopeNode* node){next = node;}
+  void SetState(NodeState new_state){state = new_state;}
+  void SetData(int new_data){data = new_data;}
+  void Reset();
+};
+
+class DopeLinkedList {
+  DopeNode nodes[MAX_DOPE_NODES];
+  DopeNode* head;
+
+public:
+  DopeLinkedList();
+  void AppendData(int init_data);
+  DopeNode* GetHead(){return head;}
+  void SetHead(DopeNode* new_head){head = new_head;}
+};
diff --git a/libs/dope/meson.build b/libs/dope/meson.build
new file mode 100644
index 0000000..ca02567
--- /dev/null
+++ b/libs/dope/meson.build
@@ -0,0 +1,3 @@
+dope_srcs = ['linkedlist.cpp']
+
+dope_lib = static_library('dope', dope_srcs)
diff --git a/libs/dope/queues.cpp b/libs/dope/queues.cpp
new file mode 100644
index 0000000..5d296a8
--- /dev/null
+++ b/libs/dope/queues.cpp
@@ -0,0 +1 @@
+#include <dope/queues.hpp>
diff --git a/libs/dope/queues.hpp b/libs/dope/queues.hpp
new file mode 100644
index 0000000..6f70f09
--- /dev/null
+++ b/libs/dope/queues.hpp
@@ -0,0 +1 @@
+#pragma once
diff --git a/libs/dope/stacks.hpp b/libs/dope/stacks.hpp
new file mode 100644
index 0000000..52e63d4
--- /dev/null
+++ b/libs/dope/stacks.hpp
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <stdlib.h>
+
+template <class T, size_t S>
+class DopeStack{
+  static const size_t size = S;
+  T stack[S];
+  T* head;
+  size_t occupancy;
+public:
+  DopeStack();
+  T pop();
+  void push(T item);
+  T peek();
+  size_t getOccupancy(){return occupancy;}
+  bool isEmpty();
+};
+
+// Implementation ____________________________________________________
+
+template <class T, size_t S>
+DopeStack<T, S>::DopeStack():
+  head (&stack[0]),
+  occupancy(0)
+{
+
+}
+
+template <class T, size_t S>
+T DopeStack<T, S>::pop(){
+  T ret = *head;
+  if(head != &stack[0]){
+    head--;
+  }
+
+  occupancy--;
+  return ret;
+}
+
+template <class T, size_t S>
+void DopeStack<T, S>::push(T item){
+  if(occupancy != 0){
+    head++;
+  }
+
+  *head = item;
+  occupancy++;
+}
+
+template <class T, size_t S>
+T DopeStack<T, S>::peek(){
+  return *head;
+}
+
+template <class T, size_t S>
+bool DopeStack<T, S>::isEmpty(){
+  return (occupancy == 0);
+}
diff --git a/libs/meson.build b/libs/meson.build
new file mode 100644
index 0000000..07a9a34
--- /dev/null
+++ b/libs/meson.build
@@ -0,0 +1,6 @@
+libs_includes = include_directories('.')
+
+subdir('dope')
+subdir('chapter1')
+subdir('chapter2')
+subdir('chapter12')
diff --git a/meson.build b/meson.build
new file mode 100644
index 0000000..f015ed0
--- /dev/null
+++ b/meson.build
@@ -0,0 +1,9 @@
+project('CrackingTheCodingInterview', 'cpp',
+        version: '0.1',
+        default_options : [
+          'warning_level=3',
+        ]
+       )
+
+subdir('libs')
+subdir('tests')
diff --git a/subprojects/cpputest.wrap b/subprojects/cpputest.wrap
new file mode 100644
index 0000000..8d9c1e2
--- /dev/null
+++ b/subprojects/cpputest.wrap
@@ -0,0 +1,13 @@
+[wrap-file]
+directory = cpputest-4.0
+source_url = https://github.com/cpputest/cpputest/archive/v4.0.tar.gz
+source_filename = cpputest-4.0.tar.gz
+source_hash = 0b66d20661f232d2a6af124c4455c8ccc9a4ce72d29f6ad4877eb385faaf5108
+patch_filename = cpputest_4.0-3_patch.zip
+patch_url = https://wrapdb.mesonbuild.com/v2/cpputest_4.0-3/get_patch
+patch_hash = 75d9e997e246884df77db2c295e465f3d25a84497a337691017c86c24a0ebf93
+source_fallback_url = https://github.com/mesonbuild/wrapdb/releases/download/cpputest_4.0-3/cpputest-4.0.tar.gz
+wrapdb_version = 4.0-3
+
+[provide]
+cpputest = cpputest_dep
diff --git a/tests/meson.build b/tests/meson.build
new file mode 100644
index 0000000..559206b
--- /dev/null
+++ b/tests/meson.build
@@ -0,0 +1,11 @@
+cpputest_project = subproject('cpputest', required: true)
+cpputest = cpputest_project.get_variable('cpputest_dep')
+
+test_exe = executable(
+  'CrackingTheCodingInvterviewVerification',
+  sources: 'test.cpp',
+  dependencies: cpputest,
+  link_with: [chapter1_lib, chapter2_lib, chapter12_lib, dope_lib],
+  include_directories: libs_includes)
+
+test('Cracking The Coding Interview Test', test_exe)
diff --git a/tests/test.cpp b/tests/test.cpp
new file mode 100644
index 0000000..93882b9
--- /dev/null
+++ b/tests/test.cpp
@@ -0,0 +1,189 @@
+#include <CppUTest/CommandLineTestRunner.h>
+#include <CppUTest/TestHarness.h>
+
+#include <chapter1/chapter1.hpp>
+#include <chapter2/chapter2.hpp>
+#include <chapter12/chapter12.hpp>
+#include <dope/linkedlist.hpp>
+#include <dope/stacks.hpp>
+#include <dope/bintree.hpp>
+#include <string.h>
+
+// Chapter 1: Arrays _________________________________________________
+
+TEST_GROUP(ChapterOne){};
+
+TEST(ChapterOne, IsUnique){
+  auto const t1 = IsUnique("aabbcc", 6);
+  auto const t2 = IsUnique("abcdef", 6);
+  CHECK_FALSE(t1);
+  CHECK(t2);
+}
+
+TEST(ChapterOne, CheckPermutations){
+  const auto s1 = "Hello";
+  const auto s2 = "olleH";
+  const auto s3 = "Holaa";
+
+  auto const t1 = CheckPermutation(s1, s2, strlen(s1), strlen(s2));
+  auto const t2 = CheckPermutation(s1, s3, strlen(s1), strlen(s3));
+  CHECK(t1);
+  CHECK_FALSE(t2);
+
+}
+
+// Chapter 2: Linked Lists ___________________________________________
+
+TEST_GROUP(ChapterTwo){};
+TEST(ChapterTwo, RemoveDups){
+  auto dll = new DopeLinkedList();
+  dll->AppendData(1);
+  dll->AppendData(2);
+  dll->AppendData(2);
+  dll->AppendData(3);
+
+  remove_dups(dll);
+  auto node = dll->GetHead();
+
+  CHECK_EQUAL(1, node->GetData());
+  node = node->GetNext();
+  CHECK_EQUAL(2, node->GetData());
+  node = node->GetNext();
+  CHECK_EQUAL(3, node->GetData());
+  delete dll;
+}
+
+TEST(ChapterTwo, Reverse){
+  auto dll = new DopeLinkedList();
+  dll->AppendData(1);
+  dll->AppendData(2);
+  dll->AppendData(3);
+  dll->AppendData(100);
+
+  auto node = dll->GetHead();
+  CHECK_EQUAL(1, node->GetData());
+  reverse_linkedlist(dll);
+  node = dll->GetHead();
+  CHECK_EQUAL(100, node->GetData());
+  node = node->GetNext();
+  CHECK_EQUAL(3, node->GetData());
+  node = node->GetNext();
+  CHECK_EQUAL(2, node->GetData());
+  node = node->GetNext();
+  CHECK_EQUAL(1, node->GetData());
+  CHECK_EQUAL(nullptr, node->GetNext());
+
+  delete dll;
+}
+
+// Chapter 3: Stacks and Queues ______________________________________
+
+TEST_GROUP(ChapterThree){};
+TEST(ChapterThree, StackMin){
+  auto stack = new DopeStack<int, 20>();
+  stack->push(10);
+  stack->push(25);
+  stack->push(42);
+  stack->push(100);
+  stack->push(2);
+
+  CHECK_EQUAL(2, stack->peek());
+  CHECK_EQUAL(2, stack->pop());
+  CHECK_EQUAL(100, stack->pop());
+  CHECK_FALSE(stack->isEmpty());
+  (void)stack->pop();
+  (void)stack->pop();
+  (void)stack->pop();
+  CHECK_TRUE(stack->isEmpty());
+  delete stack;
+}
+
+// Chapter 4: Trees __________________________________________________
+TEST_GROUP(ChapterFour){};
+TEST(ChapterFour, BinaryTrees){
+  auto btree = DopeBinTree<int>();
+  btree.insert(1);
+  btree.insert(2);
+  btree.insert(3);
+  btree.insert(4);
+  btree.insert(5);
+  btree.insert(6);
+  btree.insert(7);
+  btree.insert(8);
+
+
+  auto root = btree.getRoot();
+  CHECK_EQUAL(1, root->GetData());
+  CHECK_EQUAL(2, root->GetLeft()->GetData());
+  CHECK_EQUAL(3, root->GetRight()->GetData());
+  CHECK_EQUAL(4, root->GetLeft()->GetLeft()->GetData());
+  CHECK_EQUAL(5, root->GetLeft()->GetRight()->GetData());
+  CHECK_EQUAL(6, root->GetRight()->GetLeft()->GetData());
+  CHECK_EQUAL(7, root->GetRight()->GetRight()->GetData());
+  CHECK_EQUAL(8, root->GetLeft()->GetLeft()->GetLeft()->GetData());
+
+}
+
+TEST(ChapterFour, TreeTraversal){
+  auto btree = DopeBinTree<int>();
+  btree.insert(1); // Root
+  btree.insert(2);
+  btree.insert(3);
+  btree.insert(4);
+  btree.insert(5);
+  btree.insert(6);
+  btree.insert(7);
+
+  int array[10] = {};
+
+  btree.RecPreOrderTraversalArray(array);
+  CHECK_EQUAL(1, array[0]);
+  CHECK_EQUAL(2, array[1]);
+  CHECK_EQUAL(4, array[2]);
+  CHECK_EQUAL(5, array[3]);
+  CHECK_EQUAL(3, array[4]);
+  CHECK_EQUAL(6, array[5]);
+  CHECK_EQUAL(7, array[6]);
+
+  std::fill(array, array+10, 0);
+
+  btree.RecInOrderTraversalArray(array);
+  CHECK_EQUAL(4, array[0]);
+  CHECK_EQUAL(2, array[1]);
+  CHECK_EQUAL(5, array[2]);
+  CHECK_EQUAL(1, array[3]);
+  CHECK_EQUAL(6, array[4]);
+  CHECK_EQUAL(3, array[5]);
+  CHECK_EQUAL(7, array[6]);
+
+  std::fill(array, array+10, 0);
+
+  btree.RecPostOrderTraversalArray(array);
+  CHECK_EQUAL(4, array[0]);
+  CHECK_EQUAL(5, array[1]);
+  CHECK_EQUAL(2, array[2]);
+  CHECK_EQUAL(6, array[3]);
+  CHECK_EQUAL(7, array[4]);
+  CHECK_EQUAL(3, array[5]);
+  CHECK_EQUAL(1, array[6]);
+
+}
+
+TEST(ChapterFour, MinHeap){
+  auto btree = DopeBinTree<int>();
+
+
+}
+
+// Chapter 12: C/C++ _________________________________________________
+
+TEST_GROUP(ChapterTwelve){};
+TEST(ChapterTwelve, ReverseString){
+  char s1[] = "Hello";
+  reverse_str(s1);
+  STRCMP_EQUAL("olleH", s1);
+}
+
+int main (int ac, char** av){
+  return CommandLineTestRunner::RunAllTests(ac, av);
+}