Wrote bulk of code, added documentation

operations_on_datastructures/circular_linked_list.cpp

@@ -2,10 +2,10 @@
  * @file
  * @brief Implementation for a [Circular Linked
  * List](https://www.geeksforgeeks.org/circular-linked-list/).
- * @details The Union of two arrays is the collection of all the unique elements
- * in the first array, combined with all of the unique elements of a second
- * array. This implementation uses ordered arrays, and an algorithm to correctly
- * order them and return the result as a new array (vector).
+ * @details A Circular Linked List is a variation on the regular linked list, in
+ * which the last node has a pointer to the first node, which creates a full
+ * circle. Consequently, this allows any node to be used as the starting point
+ * for the list.
  * @author [Alvin](https://github.com/polarvoid)
  */
 
@@ -26,7 +26,7 @@ namespace operations_on_datastructures {
 namespace circular_linked_list {
 
 /**
- * @brief A Node struct that represents a single node in a Binary Tree
+ * @brief A Node struct that represents a single Node in a Binary Tree
  */
 struct Node {
     int64_t data;  ///< The value of the Node
@@ -52,8 +52,8 @@ struct Node {
  */
 class CircularLinkedList {
  private:
-    Node* root;  ///< Pointer to the root node
-    Node* end;   ///< Pointer to the last node
+    Node* root;  ///< Pointer to the root Node
+    Node* end;   ///< Pointer to the last Node
 
  public:
     /**
@@ -63,6 +63,102 @@ class CircularLinkedList {
         root = nullptr;
         end = nullptr;
     }
+    /**
+     * @brief Inserts all the values from a vector into the Circular Linked List
+     * @details Goes through each element in the vector sequentially, inserting
+     * it into the list
+     * @param values The vector of integer values that is to be inserted
+     * @returns void
+     */
+    void insert(std::vector<int64_t> values) {
+        for (int64_t value : values) {
+            insert(value);
+        }
+    }
+    /**
+     * @brief Inserts a single value into the Circular Linked List
+     * @details Creates a Node with the given value, pointing to the root Node
+     * and inserts it into the list
+     * @param data The integer valus to be inserted
+     * @returns void
+     */
+    void insert(int64_t data) {
+        Node* node = new Node(data, root);
+        insert(node);
+    }
+    /**
+     * @brief Inserts a given Node into the Circular Linked List
+     * @details Checks wheter the list is empty, and inserts the Node, modifying
+     * the end pointer
+     * @param node The Node that is to be inserted
+     * @returns void
+     */
+    void insert(Node* node) {
+        if (root == nullptr) {
+            root = node;        ///< Set node as the root
+            node->next = root;  ///< Point node to itself
+            end = root;         ///< Set the end to the root
+        } else {
+            end->next = node;   ///< Append node to the end
+            node->next = root;  ///< Set the next value to the root
+            end = node;         ///< Make end point to node
+        }
+    }
+    /**
+     * @brief Prints the values of the Circular Linked List, beginning from the
+     * root Node
+     * @details Goes through each Node from the root and prints them out in
+     * order
+     * @returns void
+     */
+    void print() { print(root); }
+    /**
+     * @brief Prints the values of the Circular Linked List, beginning from a
+     * given Node to be used as the root
+     * @details Goes through each Node from the given Node and prints them out
+     * in order. If the list is empty, it prints the message 'Empty List!'
+     * @param root The Node to start at
+     * @returns void
+     */
+    void print(Node* root) {
+        Node* temp = root;
+        if (root == nullptr) {
+            std::cout << "Empty List!\n";
+            return;
+        }
+        do {
+            std::cout << temp->data << " ";
+            temp = temp->next;
+        } while (temp != root);
+        std::cout << "\n";
+    }
+    /**
+     * @brief Returns a std::vector of the values of the Circular Linked List
+     * @details Starting from the root Node, appends each value of the list to a
+     * std::vector and returns it
+     * @returns A std::vector of the list's values
+     */
+    std::vector<int64_t> values() { return values(root); }
+    /**
+     * @brief Returns a std::vector of the values of the Circular Linked List,
+     * beginning from a given Node
+     * @details Starting from a given Node, appends each value of the list to a
+     * std::vector and returns it
+     * @param root The Node to start at
+     * @returns A std::vector of the list's values
+     */
+    std::vector<int64_t> values(Node* root) {
+        std::vector<int64_t> res;
+        if (root == nullptr) {
+            return res;  ///< Return empty vector
+        }
+        Node* temp = root;
+        do {
+            res.push_back(temp->data);
+            temp = temp->next;
+        } while (temp != root);
+        return res;
+    }
 };
 
 }  // namespace circular_linked_list
@@ -73,13 +169,101 @@ class CircularLinkedList {
  * @namespace tests
  * @brief Testcases to check Circular Linkedd List.
  */
-namespace tests {}  // namespace tests
-
+namespace tests {
+using operations_on_datastructures::circular_linked_list::CircularLinkedList;
+using operations_on_datastructures::circular_linked_list::Node;
 /**
- * @brief Function to test the correctness of the circular linked list
+ * @brief A Test to check a single value
  * @returns void
  */
-static void test() {}
+void test1() {
+    std::cout << "TEST CASE 1\n";
+    std::cout << "Intialized a = {2}\n";
+    std::cout << "Expected result: {2}\n";
+    CircularLinkedList a;
+    std::vector<int64_t> res = {2};
+    a.insert(2);
+    assert(a.values() == res);
+    a.print();
+    std::cout << "TEST PASSED!\n\n";
+}
+/**
+ * @brief A Test to check a few values
+ * @returns void
+ */
+void test2() {
+    std::cout << "TEST CASE 2\n";
+    std::cout << "Intialized a = {2, 5, 6}\n";
+    std::cout << "Expected result: {2, 5, 6}\n";
+    CircularLinkedList a;
+    std::vector<int64_t> res = {2, 5, 6};
+    a.insert(2);
+    a.insert(5);
+    a.insert(6);
+    assert(a.values() == res);
+    a.print();
+    std::cout << "TEST PASSED!\n\n";
+}
+/**
+ * @brief A Test to check an input array
+ * @returns void
+ */
+void test3() {
+    std::cout << "TEST CASE 3\n";
+    std::cout << "Intialized a = {2, 7, 8, 3, 2, 6}\n";
+    std::cout << "Expected result: {2, 7, 8, 3, 2, 6}\n";
+    CircularLinkedList a;
+    std::vector<int64_t> res = {2, 7, 8, 3, 2, 6};
+    a.insert({2, 7, 8, 3, 2, 6});
+    a.print();
+    assert(a.values() == res);
+    std::cout << "TEST PASSED!\n\n";
+}
+/**
+ * @brief A Test to check using a specific Node as the starting point
+ * @returns void
+ */
+void test4() {
+    std::cout << "TEST CASE 4\n";
+    std::cout << "Intialized a = {2, 5}\n";
+    std::cout << "Expected result: {5, 2}\n";
+    CircularLinkedList a;
+    std::vector<int64_t> res = {5, 2};
+    a.insert(2);
+    Node* start = new Node(5);  ///< Node we will start printing from
+    a.insert(start);
+    assert(a.values(start) == res);
+    a.print(start);
+    std::cout << "TEST PASSED!\n\n";
+}
+
+/**
+ * @brief A Test to check an empty list
+ * @returns void
+ */
+void test5() {
+    std::cout << "TEST CASE 5\n";
+    std::cout << "Intialized a = {}\n";
+    std::cout << "Expected result: Empty List!\n";
+    CircularLinkedList a;
+    std::vector<int64_t> res = {};
+    assert(a.values() == res);
+    a.print();
+    std::cout << "TEST PASSED!\n\n";
+}
+}  // namespace tests
+
+/**
+ * @brief Function to test the correctness of the Circular Linked List
+ * @returns void
+ */
+static void test() {
+    tests::test1();
+    tests::test2();
+    tests::test3();
+    tests::test4();
+    tests::test5();
+}
 
 /**
  * @brief main function