Added linked list files

DSA/Cpp/Linked_List/circular-doubly-linked-list.cpp

@@ -0,0 +1,89 @@
+#include <iostream>
+using namespace std;
+
+class Node{
+    public:
+    int data;
+    Node *next,*prev;
+};
+
+void push(Node **head,int datum){
+    Node *new_node=new Node();
+    new_node->data=datum;
+
+    if(*head==NULL){
+        *head=new_node;
+        new_node->next=new_node;
+        new_node->prev=new_node;
+    }else{
+        new_node->next=*head;
+        new_node->prev= (*head)->prev;
+        (*head)->prev->next=new_node;
+        *head=new_node;
+    }
+}
+
+
+void add(Node **head,int datum){
+    Node *new_node=new Node();
+    new_node->data=datum;
+
+    Node *temp=*head;
+
+    while(temp->next!=*head){
+        temp=temp->next;
+    }
+
+    new_node->next=temp->next;
+    temp->next->prev=new_node;
+    temp->next=new_node;
+    new_node->prev=temp;
+
+}
+
+void delete_last(Node **head){
+    Node* temp= *head;
+    while(temp->next!=*head){
+        temp=temp->next;
+    }
+    temp->prev->next=temp->next;
+    temp->next->prev=temp->prev;
+    delete temp;
+}
+
+void delete_top(Node **head){
+    if(*head==NULL){
+        cout<<"NULL list"<<endl;
+        return;
+    }else{
+        (*head)->prev->next=(*head)->next;
+        (*head)->next->prev=(*head)->prev;
+        (*head)=(*head)->next;
+    }
+}
+
+void display(Node* head){
+    Node *temp=head;
+    while(temp->next!=head){
+        if(temp==head){
+            cout<<"head : ";
+        }
+        cout<<temp->data<<"<->";
+        temp=temp->next;
+    }
+    cout<<temp->data<<endl;
+}
+
+
+int main(){
+    Node *head=NULL;
+    push(&head,1);
+    push(&head,2);
+    push(&head,3);
+    add(&head,5);
+    display(head);
+    delete_last(&head);
+    display(head);
+    delete_top(&head);
+    display(head);
+}

DSA/Cpp/Linked_List/circular-linked-list.cpp

@@ -0,0 +1,133 @@
+#include <iostream>
+using namespace std;
+
+class Node
+{
+public:
+    int data;
+    Node *next;
+};
+
+void delete_value(Node **head, int datum)
+{
+    Node *temp = *head;
+    if (temp == NULL)
+    {
+        cout << "NULL LIST" << endl;
+        return;
+    }
+    else
+    {
+        while (temp->next != *head && temp->next->data != datum)
+        {
+            temp = temp->next;
+        }
+        if (temp->next == *head)
+        {
+            if (temp->next->data == datum)
+            {
+                temp->next = temp->next->next;
+                *head = temp->next->next;
+            }
+            else
+            {
+                cout << "Value does not exist" << endl;
+                return;
+            }
+        }
+        else
+        {
+            temp->next = temp->next->next;
+        }
+    }
+}
+void add(Node **head, int data)
+{
+    Node *new_node = new Node();
+    new_node->data = data;
+
+    Node *temp = *head;
+    if (*head == NULL)
+    {
+        *head = new_node;
+        new_node->next = new_node;
+        return;
+    }
+    while (temp->next != *head)
+    {
+        temp = temp->next;
+    }
+    temp->next = new_node;
+    new_node->next = *head;
+}
+void push(Node **head, int data)
+{
+    Node *new_node = new Node();
+    Node *temp = *head;
+
+    new_node->data = data;
+
+    if (*head == NULL)
+    {
+        new_node->next = new_node;
+        *head = new_node;
+        return;
+    }
+    else
+    {
+        while (temp && temp->next != (*head))
+        {
+            temp = temp->next;
+        }
+        temp->next = new_node;
+        new_node->next = *head;
+        *head = new_node;
+    }
+}
+
+void delete_from_end(Node **head)
+{
+    Node *temp = *head;
+    if (temp == NULL)
+    {
+        cout << "NULL LIST" << endl;
+        return;
+    }
+    else
+    {
+        while (temp->next->next != *head)
+        {
+            temp = temp->next;
+        }
+        temp->next = temp->next->next;
+    }
+}
+
+void display(Node *head)
+{
+    Node *temp = head;
+    while (temp->next != head)
+    {
+        if (head == temp)
+        {
+            cout << "head : ";
+        }
+        cout << temp->data << " -> ";
+        temp = temp->next;
+    }
+    cout << temp->data;
+}
+
+int main()
+{
+    Node *head = NULL;
+    push(&head, 1);
+    push(&head, 2);
+    push(&head, 3);
+    push(&head,5);
+    add(&head, 4);
+    display(head);
+    delete_from_end(&head);
+    delete_value(&head, 5);
+    display(head);
+}

DSA/Cpp/Linked_List/doubly-linked-list.cpp

@@ -0,0 +1,118 @@
+#include <iostream>
+using namespace std;
+
+class Node
+{
+public:
+    int data;
+    Node *prev;
+    Node *next;
+};
+
+void insert_after_value(Node **head, int datum, int after)
+{
+    Node *temp = *head;
+    Node *new_node = new Node();
+
+    new_node->data = datum;
+
+    while (temp != NULL && temp->data != after)
+    {
+        temp = temp->next;
+    }
+    if (temp == NULL)
+    {
+        cout << "Value does not exist in doubly linked list" << endl;
+    }
+    else
+    {
+        new_node->next = temp->next;
+        new_node->prev = temp;
+        temp->next = new_node;
+    }
+}
+
+void push(Node **head, int datum)
+{
+
+    Node *new_node = new Node();
+    new_node->data = datum;
+
+    new_node->next = *head;
+    new_node->prev = NULL;
+
+    if ((*head) != NULL)
+    {
+        (*head)->prev = new_node;
+    }
+
+    (*head) = new_node;
+}
+
+void append(Node **head, int datum)
+{
+    Node *temp = *head;
+    Node *new_node = new Node();
+    new_node->data = datum;
+    new_node->next = NULL;
+
+    if (*head == NULL)
+    {
+        new_node->prev = NULL;
+        *head = new_node;
+    }
+
+    while (temp->next != NULL)
+    {
+        temp = temp->next;
+    }
+    temp->next = new_node;
+    new_node->prev = temp;
+}
+
+void Node_delete(Node **head, int val)
+{
+    Node *temp = *head;
+    while (temp != NULL && temp->data != val)
+    {
+        temp = temp->next;
+    }
+    if (temp == NULL)
+    {
+        cout << "Node not found" << endl;
+    }
+    else
+    {
+        (temp->prev)->next = temp->next;
+        (temp->next)->prev = temp->prev;
+    }
+}
+
+
+void display(Node *head)
+{
+    Node *temp = new Node();
+    temp = head;
+    while (temp != NULL)
+    {
+        if (temp == head)
+        {
+            cout << "head:";
+        }
+        cout << temp->data << " <-> ";
+        temp = temp->next;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    Node *head = NULL;
+    push(&head, 7);
+    push(&head, 8);
+    append(&head, 6);
+    insert_after_value(&head, 99, 7);
+    display(head);
+    Node_delete(&head,7);
+    display(head);
+}