chore: import upstream snapshot with attribution

data_structures/cll/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_executable( cll 
+    cll.cpp 
+    main_cll.cpp 
+)
+install(TARGETS cll DESTINATION "bin/data_structures")

data_structures/cll/cll.cpp

@@ -0,0 +1,110 @@
+/*
+    A simple class for Cicular Linear Linked List
+*/
+#include "cll.h"
+using namespace std;
+
+/* Constructor */
+cll::cll() {
+    head = NULL;
+    total = 0;
+}
+
+cll::~cll() { /* Desstructure, no need to fill */
+}
+
+/* Display a list. and total element */
+void cll::display() {
+    if (head == NULL)
+        cout << "List is empty !" << endl;
+    else {
+        cout << "CLL list: ";
+        node *current = head;
+        for (int i = 0; i < total; i++) {
+            cout << current->data << " -> ";
+            current = current->next;
+        }
+        cout << head->data << endl;
+        cout << "Total element: " << total << endl;
+    }
+}
+
+/* List insert a new value at head in list */
+void cll::insert_front(int new_data) {
+    node *newNode;
+    newNode = new node;
+    newNode->data = new_data;
+    newNode->next = NULL;
+    if (head == NULL) {
+        head = newNode;
+        head->next = head;
+    } else {
+        node *current = head;
+        while (current->next != head) {
+            current = current->next;
+        }
+        newNode->next = head;
+        current->next = newNode;
+        head = newNode;
+    }
+    total++;
+}
+
+/* List insert a new value at head in list */
+void cll::insert_tail(int new_data) {
+    node *newNode;
+    newNode = new node;
+    newNode->data = new_data;
+    newNode->next = NULL;
+    if (head == NULL) {
+        head = newNode;
+        head->next = head;
+    } else {
+        node *current = head;
+        while (current->next != head) {
+            current = current->next;
+        }
+        current->next = newNode;
+        newNode->next = head;
+    }
+    total++;
+}
+
+/* Get total element in list */
+int cll::get_size() { return total; }
+
+/* Return true if the requested item (sent in as an argument)
+is in the list, otherwise return false */
+bool cll::find_item(int item_to_find) {
+    if (head == NULL) {
+        cout << "List is empty !" << endl;
+        return false;
+    } else {
+        node *current = head;
+        while (current->next != head) {
+            if (current->data == item_to_find)
+                return true;
+            current = current->next;
+        }
+        return false;
+    }
+}
+
+/* Overloading method*/
+int cll::operator*() { return head->data; }
+
+/* Overload the pre-increment operator.
+   The iterator is advanced to the next node. */
+void cll::operator++() {
+    if (head == NULL) {
+        cout << "List is empty !" << endl;
+    } else {
+        node *current = head;
+        while (current->next != head) {
+            current = current->next;
+        }
+        current->next = head->next;
+        head = head->next;
+    }
+    total--;
+}

data_structures/cll/cll.h

@@ -0,0 +1,43 @@
+/*
+ * Simple data structure CLL (Circular Linear Linked List)
+ * */
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
+#include <iostream>
+
+#ifndef CLL_H
+#define CLL_H
+/*The data structure is a linear linked list of integers */
+struct node {
+    int data;
+    node* next;
+};
+
+class cll {
+ public:
+    cll(); /* Construct without parameter */
+    ~cll();
+    void display(); /* Show the list */
+
+    /******************************************************
+     * Useful method for list
+     *******************************************************/
+    void insert_front(int new_data);  /* Insert a new value at head  */
+    void insert_tail(int new_data);   /* Insert a new value at tail */
+    int get_size();                   /* Get total element in list */
+    bool find_item(int item_to_find); /* Find an item in list */
+
+    /******************************************************
+     * Overloading method for list
+     *******************************************************/
+    int operator*(); /* Returns the info contained in head */
+    /* Overload the pre-increment operator.
+       The iterator is advanced to the next node. */
+    void operator++();
+
+ protected:
+    node* head;
+    int total; /* Total element in a list */
+};
+#endif

data_structures/cll/main_cll.cpp

@@ -0,0 +1,43 @@
+#include "cll.h"
+using namespace std;
+
+int main() {
+    /* Test CLL */
+    cout << "----------- Test construct -----------" << endl;
+    cll list1;
+    list1.display();
+    cout << "----------- Test insert front -----------" << endl;
+    list1.insert_front(5);
+    cout << "After insert 5 at front: " << endl;
+    list1.display();
+    cout << "After insert 10 3 7 at front: " << endl;
+    list1.insert_front(10);
+    list1.insert_front(3);
+    list1.insert_front(7);
+    list1.display();
+    cout << "----------- Test insert tail -----------" << endl;
+    cout << "After insert 18 19 20 at tail: " << endl;
+    list1.insert_tail(18);
+    list1.insert_tail(19);
+    list1.insert_tail(20);
+    list1.display();
+    cout << "----------- Test find item -----------" << endl;
+    if (list1.find_item(10))
+        cout << "PASS" << endl;
+    else
+        cout << "FAIL" << endl;
+    if (!list1.find_item(30))
+        cout << "PASS" << endl;
+    else
+        cout << "FAIL" << endl;
+    cout << "----------- Test * operator -----------" << endl;
+    int value = *list1;
+    cout << "Value at *list1: " << value << endl;
+    cout << "----------- Test ++ operator -----------" << endl;
+    list1.display();
+    ++list1;
+    cout << "After ++list1: " << endl;
+    list1.display();
+
+    return 0;
+}