Reorganize files

cpp/datastructs/circledoublelist/Makefile

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+CXX=g++
+CXXFLAGS=-g -Wall
+
+###############################################################################
+# Driver
+###############################################################################
+
+driver:	driver.cpp	circledoublelist.o
+	${CXX} ${CXXFLAGS} driver.cpp circledoublelist.o -o driver
+
+###############################################################################
+# CircleDoubleList
+###############################################################################
+
+circledoublelist.o:	circledoublelist.cpp circledoublelist.h
+	${CXX} ${CXXFLAGS} -c circledoublelist.cpp -o circledoublelist.o
+
+###############################################################################
+# Clean
+###############################################################################
+
+clean:
+	rm -f *.o driver

cpp/datastructs/circledoublelist/circledoublelist.cpp

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+/*#############################################################################
+## Author: Shaun Reed                                                        ##
+## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## About: An example of a circular doubly linked list                        ##
+##                                                                           ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
+##############################################################################
+## circledoublelist.cpp
+*/
+
+#include "circledoublelist.h"
+
+
+/******************************************************************************
+ * Constructors, Destructors, Operators
+ *****************************************************************************/
+
+/** copy constructor
+ * @brief Construct a new CircleDoubleList::CircleDoubleList object from an existing one
+ *
+ * @param rhs CircleDoubleList object
+ */
+CircleDoubleList::CircleDoubleList(const CircleDoubleList& rhs)
+{
+  Node *cp = rhs.tail;
+  Node *tempHead;
+  if (cp == NULL) tail = NULL;
+  else {
+    tail = new Node(cp->data);
+    tempHead = tail;
+    while (cp->next != NULL) {
+      cp = cp->next;
+      tail->next = new Node(cp->data);
+      tail = tail->next;
+    }
+    tail = tempHead;
+  }
+}
+
+/** operator=
+ * @brief Assign two CircleDoubleList objects equal using copy constr and class destr
+ *        Pass the rhs by value to create local copy, swap its contents
+ *        Destructor called on previous CircleDoubleList data at the end of this scope
+ *
+ * @param rhs CircleDoubleList object passed by value
+ * @return CircleDoubleList A deep copy of the rhs CircleDoubleList object
+ */
+CircleDoubleList CircleDoubleList::operator=(CircleDoubleList rhs)
+{
+  if (this != &rhs) return *this;
+  std::swap(tail, rhs.tail);
+  return *this;
+}
+
+/** destructor
+ * @brief Destroy the CircleDoubleList::CircleDoubleList object
+ */
+CircleDoubleList::~CircleDoubleList()
+{
+  makeEmpty();
+}
+
+
+/******************************************************************************
+ * Public Member Functions
+ *****************************************************************************/
+
+/** insert
+ * @brief Inserts a value to the head of our linked list
+ *
+ * @param val The value to be inserted
+ */
+bool CircleDoubleList::insert(int val)
+{
+  bool inserted = insert(val, tail);
+  if (inserted)
+    std::cout << "[" << val << "] was inserted into the list\n";
+  else std::cout << "[" << val << "] could not be inserted into the list\n";
+  return inserted;
+}
+
+/** insert at
+ * @brief Inserts a value in the place of a given key
+ *        Key Node found is moved to the newNode->next positon
+ *
+ * @param key The value to search for to determine insert location
+ * @param val The value to be inserted into the list
+ */
+bool CircleDoubleList::insert(int val, int key)
+{
+  // Check that we are not trying to insert at a position within an empty list
+  if (tail == NULL) {
+    std::cout << "Cannot insert at a key value using an empty list\n";
+    return false;
+  }
+
+  bool inserted = insert(val, key, tail->next);
+  if (inserted)
+    std::cout << "[" << val << "] was inserted into the list\n";
+  else std::cout << "[" << val << "] could not be inserted into the list\n";
+  return inserted;
+}
+
+/** remove
+ * @brief Removes a value in the list by calling overloaded private member and handling output
+ *
+ * @param val Value to be removed from the list
+ * @return true If the value was removed from the list
+ * @return false If the value was not removed from the list
+ */
+bool CircleDoubleList::remove(int val)
+{
+  // Check that we are not trying to remove from an empty list
+  if (isEmpty()) {
+    std::cout << "Cannot remove from an empty list\n";
+    return false;
+  }
+
+  // Attempt to remove the item
+  bool removed = remove(val, tail->next);
+  if (removed)
+    std::cout << "[" << val << "] was removed from the list\n";
+  else std::cout << "[" << val << "] could not be removed from the list\n";
+  return removed;
+}
+
+/** replace
+ * @brief Replaces a value in the list by calling overloaded private member and handling output
+ *
+ * @param val Value to insert into the list
+ * @param key Value to be replaced within the list
+ * @return true If the key has been replaced in the list by val
+ * @return false If the key has not been replaced in the list by val
+ */
+bool CircleDoubleList::replace(int val, int key)
+{
+  // Check that we are not trying to replace within an empty list
+  if (isEmpty()) {
+    std::cout << "Cannot replace anything within an empty list\n";
+    return false;
+  }
+
+  // Attempt to replace the item
+  bool replaced = replace(val, key, tail->next);
+  if (replaced)
+    std::cout << "[" << key << "] was replaced by [" << val << "] in the list\n";
+  else std::cout << "[" << key << "] could not be replaced by [" << val << "] in the list\n";
+  return replaced;
+}
+
+/** makeEmpty
+ * @brief Empty this CircleDoubleList object, deleting all associated Nodes
+ */
+void CircleDoubleList::makeEmpty()
+{
+  Node *nextNode;
+  if (isEmpty()) return;
+  
+  // Start deletion from the head of the list
+  nextNode = tail->next;
+  while(!isEmpty()) {
+    nextNode = nextNode->next;
+    remove(nextNode->prev->data);
+  }
+  nextNode = NULL;
+  return;
+}
+
+/** isEmpty
+ * @brief Determine if the CircleDoubleList is empty
+ *
+ * @return true If the CircleDoubleList::tail is NULL
+ * @return false If the CircleDoubleList::tail contains data
+ */
+bool CircleDoubleList::isEmpty() const
+{
+  return tail == NULL;
+}
+
+/** peek
+ * @brief returns the value at the CircleDoubleList::head
+ *
+ * @return int The value held at the Node pointed to by CircleDoubleList::head
+ */
+int CircleDoubleList::peek() const
+{
+  if (!isEmpty())
+    std::cout << "[" << tail->next->data << "] is at the top of our list\n";
+  else std::cout << "Nothing to peek, our list is empty...\n";
+  return tail->data;
+}
+
+/** print
+ * @brief Output the data held by the CircleDoubleList object
+ *        Calls to the private print()
+ */
+void CircleDoubleList::print() const
+{
+  // Print from the head of our list
+  if(!isEmpty()) print(tail->next);
+  else std::cout << "Nothing to print, our list is empty...\n";
+}
+
+/** find
+ * @brief Calls to overloaded private member find() and handles output
+ *
+ * @param val The value to search for within our CircleDoubleList
+ * @return true If the value was found in this CircleDoubleList
+ * @return false If the value was not found in this CircleDoubleList
+ */
+bool CircleDoubleList::find(int val) const
+{
+  // Check that we are not trying to search an empty list
+  if (isEmpty()) {
+    std::cout << "Cannot search an empty list\n";
+    return false;
+  }
+
+  Node *result = find(val, tail);
+  if( result == NULL) {
+    std::cout << "[" << val << "] Was not found in our list\n";
+    return false;
+  }
+
+  std::cout << "[" << result->data << "] Was found in our list\n";
+  return true;
+}
+
+
+/******************************************************************************
+ * Private Member Functions
+ *****************************************************************************/
+
+/** insert
+ * @brief Private member to handle inserting value into the list
+ *
+ * @param val Value to be inserted
+ * @param tail The tail node of the list to insert the value into
+ * @return true If the value was inserted
+ * @return false If the value could not be inserted
+ */
+bool CircleDoubleList::insert(int val, Node *&tail)
+{
+  Node *newNode = new Node(val);
+  if (!isEmpty()) {
+    // Relink the current head to the node after newNode
+    newNode->next = tail->next;
+    tail->next->prev = newNode;
+    // Relink our head and tail nodes, makine newNode the head node
+    tail->next = newNode;
+    newNode->prev = tail;
+  }
+  else tail = newNode;
+  return true;
+}
+
+/** insert at
+ * @brief Private member to handle inserting a value at a key within our list
+ *
+ * @param val Value to be inserted
+ * @param key Key value to search for within the list
+ * @param head Head node of the list to insert to
+ * @return true If the value was inserted
+ * @return false If the value was not inserted
+ */
+bool CircleDoubleList::insert(int val, int key, Node *&head)
+{
+  Node *newNode = new Node(val);
+  // Let insert() handle inserting at the head
+  if (head->data == key) return insert(val);
+
+  // Get the node which contains our value
+  Node *keyNode = find(key, head);
+  // If there was no keyNode found, the key is not in our list, do nothing
+  if (keyNode == NULL) return false;
+  // Insert the newNode in front of the previous to the keyNode
+  // [head]->[key]->[tail]
+  // [head]->[new]->[key]->[tail]
+  newNode->prev = keyNode->prev;
+  keyNode->prev->next = newNode;
+
+  // Change the keyNode->prev ptr to newNode
+  newNode->next = keyNode;
+  keyNode->prev = newNode;
+  return true;
+}
+
+/** remove
+ * @brief Private member to remove values from the list
+ *
+ * @param val Value to be removed
+ * @param head Head of the list to remove the value from
+ * @return true If the value has been removed from the list
+ * @return false If the value has not been removed from the list
+ */
+bool CircleDoubleList::remove(int val, Node *&head)
+{
+  // If there is only one node in the list
+  // Synonymous with: if (tail = tail->next)
+  if (head == head->next) {
+    delete tail;
+    tail = NULL;
+    // Nothing to relink, list is empty
+    return true;
+  }
+  
+  // If the head node contains the value to remove
+  if (head->data == val) {
+    Node *temp = head;
+    // Move head to the next node in the list
+    head = head->next;
+    // Relink head and tail nodes
+    head->prev = tail;
+    tail->next = head;
+    // Delete dangling pointer created by relinking
+    delete temp;
+    return true;
+  }
+  
+  // If the tail node contains the value to remove
+  if (tail->data == val) {
+    Node *temp = tail;
+    // Move tail to the previous node in the list
+    tail = tail->prev;
+    // Relink head and tail nodes
+    head->prev = tail;
+    tail->next = head;
+    // Delete dangling pointer created by relinking
+    delete temp;
+    return true;
+  }
+
+  // Search for the value further within our list
+  Node *keyNode = find(val, head);
+  // If NULL, the value does not exist within our list
+  if (keyNode == NULL) return false;
+  // Relink surrounding nodes to make keyNode a dangling ptr
+  keyNode->next->prev = keyNode->prev;
+  keyNode->prev->next = keyNode->next;
+  // Delete the dangling node created by relinking above
+  delete keyNode;
+  keyNode = NULL;
+  return true;
+}
+
+/** replace
+ * @brief Private member to replace values within the list
+ *
+ * @param val Value to insert into the list
+ * @param key Value to be replaced within the list
+ * @param head Head node of the list to modify
+ * @return true If the key has been replaced by val within the list
+ * @return false If the key has not been replaced by val within the list
+ */
+bool CircleDoubleList::replace(int val, int key, Node *&head)
+{
+  Node *replacee = find(key, head);
+  if (replacee == NULL) return false;
+  replacee->data = val;
+  return true;
+}
+
+/** find
+ * @brief Find and return a Node which contains the given value
+ *
+ * @param val The value to search for within our CircleDoubleList
+ * @param start The node to begin the search from, returns on the first found result
+ * @return CircleDoubleList::Node* A pointer to the Node containing the search value
+ */
+CircleDoubleList::Node* CircleDoubleList::find(int val, Node *start) const
+{
+  // If given a NULL list, return NULL
+  // If given a head which contains the requested value, return the foundNode
+  if (start == NULL || start->data == val) return start;
+
+  // Copy our start position, check its value 
+  Node *foundNode = start;
+  if (foundNode->data == val) return foundNode;
+  // Keep checking the next node until we reach the start value again
+  while (foundNode->next != start) {
+    foundNode = foundNode->next;
+    if (foundNode->data == val) return foundNode;
+  }
+  // If we have not yet returned a foundNode, the key is not in our list
+  return NULL;
+}
+
+/** print
+ * @brief Output the contents of a CircleDoubleList from the given Node to NULL
+ *
+ * @param start The Node to begin traversing output from
+ */
+void CircleDoubleList::print(Node *start) const
+{
+  Node *temp = start;
+  std::cout << "List Contents: " << temp->data << " | ";
+  temp = temp->next;
+  while (temp != start) {
+    std::cout << temp->data << " | ";
+    temp = temp->next;
+  }
+  std::cout << std::endl;
+}

cpp/datastructs/circledoublelist/circledoublelist.h

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+/*#############################################################################
+## Author: Shaun Reed                                                        ##
+## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## About: An example of a circular doubly linked list                        ##
+##                                                                           ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
+##############################################################################
+## circledoublelist.h
+*/
+
+#ifndef CIRCLEDOUBLELIST_H
+#define CIRCLEDOUBLELIST_H
+
+#include <iostream>
+
+class CircleDoubleList {
+  public:
+    CircleDoubleList() : tail(NULL) {};
+    CircleDoubleList(const CircleDoubleList& rhs);
+    CircleDoubleList operator=(CircleDoubleList rhs);
+    ~CircleDoubleList();
+    bool insert(int val);
+    bool insert(int val, int key);
+    bool remove(int val);
+    bool replace(int val, int key);
+    void makeEmpty();
+    bool isEmpty() const;
+    int peek() const;
+    void print() const;
+    bool find(int val) const;
+
+  private:
+    struct Node {
+      int data;
+      Node *next, *prev;
+      Node(): data(), next(NULL), prev(NULL) {};
+      Node(int val): data(val), next(this), prev(this) {};
+    };
+    Node *tail;
+    bool insert(int val, Node *&tail);
+    bool insert(int val, int key, Node *&tail);
+    bool remove(int val, Node *&tail);
+    bool replace(int val, int key, Node *&tail);
+    Node* find(int val, Node *start) const;
+    void print(Node *start) const;
+};
+
+#endif

cpp/datastructs/circledoublelist/driver.cpp

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+/*#############################################################################
+## Author: Shaun Reed                                                        ##
+## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## About: A driver program to test a circular doubly linked list             ##
+##                                                                           ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
+##############################################################################
+## driver.cpp
+*/
+
+#include "circledoublelist.h"
+#include <iostream>
+
+enum OPS {
+  EXIT, INSERT, INSERTAT, EMPTY, PEEK, PRINT, FIND, REMOVE, REPLACE
+};
+
+int main()
+{
+  CircleDoubleList testList;
+  bool exit = false;
+  int choice = -1;
+  int val, key;
+
+  while (!exit)
+  {
+    std::cout << "##### Circular Doubly Linked List Menu #####\n\t0. Exit"
+      << "\n\t1. Insert\n\t2. Insert at\n\t3. Empty list\n\t4. Peek top of list"
+      << "\n\t5. Print list\n\t6. Find\n\t7. Remove\n\t8. Replace\n";
+    std::cin >> choice;
+    std::cin.clear();
+    switch (choice) {
+    case EXIT:
+      exit = true;
+      break;
+
+    case INSERT:
+      std::cout << "Enter a value to add to our list: ";
+      std::cin >> val;
+      std::cin.clear();
+      testList.insert(val);
+      break;
+
+    case INSERTAT:
+      std::cout << "Enter a new value to add to our list: ";
+      std::cin >> val;
+      std::cin.clear();
+      std::cout << "Enter an existing value to insert at within our list: ";
+      std::cin >> key;
+      std::cin.clear();
+      if (testList.insert(val, key)) {
+        std::cout << "List after inserting ["
+          << val << "] at [" << key << "]: \n";
+        testList.print();
+      }
+      break;
+
+    case EMPTY:
+      testList.makeEmpty();
+      break;
+
+    case PEEK:
+      testList.peek();
+      break;
+
+    case PRINT:
+      testList.print();
+      break;
+
+    case FIND:
+      std::cout << "Enter an existing value to search for within our list: ";
+      std::cin >> val;
+      std::cin.clear();
+      testList.find(val);
+      break;
+
+    case REMOVE:
+      std::cout << "Enter an existing value to remove from our list: ";
+      std::cin >> val;
+      std::cin.clear();
+      testList.remove(val);
+      break;
+
+    case REPLACE:
+      std::cout << "Enter a new value to add to our list: ";
+      std::cin >> val;
+      std::cin.clear();
+      std::cout << "Enter an existing value to replace within our list: ";
+      std::cin >> key;
+      std::cin.clear();
+      if (testList.replace(val, key)) {
+        std::cout << "List after replacing ["
+          << key << "] by [" << val << "]: \n";
+        testList.print();
+      }
+      break;
+
+    default:
+      std::cout << "Invalid entry...\n";
+      break;
+    }
+  }
+}
+