[6] Double Linked List (#6)

* [5] LinkedList

* [6] Doubly Linked List

main.cpp

@@ -5,6 +5,8 @@
 #include "test/Numbermanipulationtest.cpp"
 #include "test/LinkedListtest.cpp"
 
+#include "src/DATA_STRUCTURES/DoublyLinkedList.cpp"
+
 #include "src/OOPS/class.cpp"
 
 using namespace std;
@@ -15,5 +17,6 @@ int main()
     test();
     class_demo();
     linkedlisttest();
+    doublyLinkedListtest();
     return 0;
 }

src/DATA_STRUCTURES/DoublyLinkedList.cpp

@@ -0,0 +1,133 @@
+#include <iostream>
+
+
+struct node {
+    int32_t val;
+    node *prev;
+    node *next;
+}*head;
+
+
+class doublyLinkedList{
+    private:
+    //node *head;
+    public:
+    doublyLinkedList() {
+        head = nullptr;
+    }
+    void insert(int8_t n);
+    void remove(int8_t idx);
+    void show();
+    void reverseShow();
+
+    ~doublyLinkedList() {
+        node* current = head;
+        while(current != nullptr)
+        {
+            node* next = current->next;
+            delete current;
+            current = next;
+        }
+        head = nullptr;
+    };
+
+};
+    void doublyLinkedList::insert(int8_t n)
+    {
+        std::cout << "Inserting: " << (int)n << std::endl;
+        node *t = head;
+
+        node *new_node = new node();
+
+        if (head != nullptr)
+        {
+        while (t->next != nullptr)
+        {
+            t = t->next;
+        }
+
+        new_node->val = n;
+        t->next = new_node;
+        new_node->next = nullptr;
+        new_node->prev = t;
+        }
+        else{
+            new_node->val = n;
+            new_node->next = nullptr;
+            new_node->prev = nullptr;
+            head = new_node;
+        }
+    }
+
+    void doublyLinkedList::show()
+    {
+        std::cout<<"Display Double linkedlist: ";
+        node *temp = head;
+        while(temp != nullptr)
+        {
+            cout << temp->val << " ";
+            temp = temp->next;
+        }
+        std::cout << std::endl;
+    }
+
+void doublyLinkedList::reverseShow()
+{
+    node* curr = head;
+    node *temp = nullptr;
+
+    while(curr != nullptr)
+    {
+        temp = curr->prev;
+        curr->prev = curr->next;
+        curr->next = temp;
+        curr = curr->prev;
+    }
+    if(temp != nullptr)
+    {
+        head = temp->prev;
+    }
+
+}
+
+void doublyLinkedList::remove(int8_t idx)
+{
+    std::cout << "Removing: " << (int)idx << std::endl;
+    node* temp = head;
+
+    while (temp != nullptr)
+    {
+        //std::cout<<"temp: "<<temp->val<<std::endl;
+        if (temp->val == idx)
+        {
+            //std::cout<<"removing: "<<temp->val<<std::endl;
+            temp->prev->next = temp->next;
+            temp->next->prev = temp->prev;
+            delete temp;
+            break;
+        }
+        temp = temp->next;
+    }
+}
+
+int doublyLinkedListtest()
+{
+    doublyLinkedList l;
+    l.insert(1);
+    l.insert(2);
+    l.insert(3);
+    l.insert(4);
+    l.insert(5);
+    l.show();
+    l.reverseShow();
+    l.show();
+    l.remove(3);
+    l.show();
+    l.reverseShow();
+    l.show();
+    l.insert(3);
+    l.show();
+    l.reverseShow();
+    l.show();
+    return 0;
+}