Updated blogs stackcrud linkedlist,linkedlist palindrome,array heap sort,finding loop, crod on doubly linked list

Doubly Linked List CRUD/LinkedList/Easy/DoubleLinkedlist.py

@@ -0,0 +1,166 @@
+class Node:
+    def __init__(self, val):
+        self.prev = None
+        self.data = val
+        self.next = None
+
+class DLL:
+    def __init__(self):
+        self.head = None
+
+    # Create Operation: Insert at the Beginning
+    def insert_begin(self, val):
+        new_node = Node(val)
+        if self.head:
+            self.head.prev = new_node
+            new_node.next = self.head
+            self.head = new_node
+        else:
+            self.head = new_node
+
+    # Create Operation: Insert at the End
+    def insert_end(self, val):
+        new_node = Node(val)
+        if self.head is None:
+            self.head = new_node
+        else:
+            temp = self.head
+            while temp.next:
+                temp = temp.next
+            new_node.prev = temp
+            temp.next = new_node
+
+    # Create Operation: Insert at a Specific Position
+    def insert_pos(self, val, pos):
+        count = 0
+        temp = self.head
+        while temp:
+            count += 1
+            if count == pos:
+                break
+            else:
+                temp = temp.next
+        new_node = Node(val)
+        new_node.prev = temp.prev
+        new_node.next = temp
+        temp.prev.next = new_node
+
+    # Delete Operation: Delete from the Beginning
+    def delete_begin(self):
+        if self.head is None:
+            print("List is empty.")
+        else:
+            self.head = self.head.next
+            if self.head:
+                self.head.prev = None
+
+    # Delete Operation: Delete from the End
+    def delete_end(self):
+        if self.head is None:
+            print("List is empty.")
+        elif self.head.next is None:
+            self.head = None
+        else:
+            temp = self.head
+            while temp.next:
+                temp = temp.next
+            temp.prev.next = None
+
+    # Delete Operation: Delete from a Specific Position
+    def delete_pos(self, pos):
+        count = 0
+        temp = self.head
+        while temp:
+            count += 1
+            if count == pos:
+                break
+            else:
+                temp = temp.next
+        if temp.next:
+            temp.next.prev = temp.prev
+            temp.prev.next = temp.next
+        else:
+            temp.prev.next = None
+
+    # Update Operation: Update Node Value
+    def update(self, pval, nval):
+        if self.head:
+            temp = self.head
+            while temp:
+                if temp.data == pval:
+                    temp.data = nval
+                    break
+                temp = temp.next
+
+    # Remove Operation: Remove Node with a Specific Value
+    def remove(self, val):
+        if self.head and self.head.data == val:
+            self.head = self.head.next
+            if self.head:
+                self.head.prev = None
+        else:
+            temp = self.head
+            while temp and temp.next:
+                if temp.data == val:
+                    temp.next.prev = temp.prev
+                    temp.prev.next = temp.next
+                    break
+                temp = temp.next
+
+    # Display Operation: Display the Doubly Linked List
+    def display(self):
+        temp = self.head
+        while temp:
+            print(temp.data, end="<->")
+            temp = temp.next
+        print("None")
+
+
+# Example Usage
+dll = DLL()
+
+while True:
+    print("\n1. Insert at the Beginning")
+    print("2. Insert at the End")
+    print("3. Insert at a Specific Position")
+    print("4. Delete from the Beginning")
+    print("5. Delete from the End")
+    print("6. Delete from a Specific Position")
+    print("7. Update Node Value")
+    print("8. Remove Node with a Specific Value")
+    print("9. Display")
+    print("0. Exit")
+
+    choice = int(input("Enter your choice: "))
+
+    if choice == 1:
+        val = int(input("Enter value to insert at the beginning: "))
+        dll.insert_begin(val)
+    elif choice == 2:
+        val = int(input("Enter value to insert at the end: "))
+        dll.insert_end(val)
+    elif choice == 3:
+        val = int(input("Enter value to insert: "))
+        pos = int(input("Enter position to insert at: "))
+        dll.insert_pos(val, pos)
+    elif choice == 4:
+        dll.delete_begin()
+    elif choice == 5:
+        dll.delete_end()
+    elif choice == 6:
+        pos = int(input("Enter position to delete: "))
+        dll.delete_pos(pos)
+    elif choice == 7:
+        pval = int(input("Enter old value to update: "))
+        nval = int(input("Enter new value: "))
+        dll.update(pval, nval)
+    elif choice == 8:
+        val = int(input("Enter value to remove: "))
+        dll.remove(val)
+    elif choice == 9:
+        dll.display()
+    elif choice == 0:
+        print("Exiting...")
+        break
+    else:
+        print("Invalid choice. Please try again.")

Doubly Linked List CRUD/LinkedList/Easy/LinkedList.cpp

@@ -0,0 +1,127 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+class Node {
+public:
+    int data;
+    Node* next;
+    Node* prev;
+
+    Node() {
+        data = 0;
+        next = NULL;
+        prev = NULL;
+    }
+
+    Node(int val) {
+        data = val;
+        next = NULL;
+        prev = NULL;
+    }
+};
+
+class DoubleLinkedList {
+private:
+    Node* head = NULL;
+    int length = 0;
+
+public:
+
+    /* Insertion operation (Create) */
+    void insert(int data) {
+        if (head == NULL) {
+            /* If the list is empty, create a new node and set it as the head*/
+            head = new Node(data);
+        }
+        else {
+            /* Otherwise, create a new node, update links, and set it as the new head */
+            Node* temp = new Node(data);
+            length++;
+            temp->next = head;
+            head->prev = temp;
+            head = temp;
+        }
+        length++;
+    }
+
+    /* Deletion operation (Delete) */
+    void del() {
+        if (head == NULL) {
+            cout << "List is empty. Cannot delete.\n";
+            return;
+        }
+        head = head->next;
+        if (head != NULL) {
+            head->prev = NULL;
+        }
+        length--;
+        cout << "Node deleted successfully.\n";
+    }
+
+    /* Display operation (Read) */
+    void print() {
+        Node* temp = head;
+        while (temp != NULL) {
+            cout << temp->data << " ";
+            temp = temp->next;
+        }
+        cout << endl;
+    }
+
+    /* Size operation (Read)*/
+    void displaySize() {
+        cout << "Size of the list: " << length << endl;
+    }
+
+    /* Main menu for user interaction */
+    void menu() {
+        int choice, data;
+
+        while (true) {
+            cout << "\nChoose operation:\n";
+            cout << "1. Insert\n";
+            cout << "2. Delete\n";
+            cout << "3. Display\n";
+            cout << "4. Display Size\n";
+            cout << "5. Exit\n";
+
+            cin >> choice;
+
+            switch (choice) {
+            case 1:
+                cout << "Enter data to insert: ";
+                cin >> data;
+                insert(data);
+                cout << "Node inserted successfully.\n";
+                break;
+
+            case 2:
+                del();
+                break;
+
+            case 3:
+                cout << "Elements in the list: ";
+                print();
+                break;
+
+            case 4:
+                displaySize();
+                break;
+
+            case 5:
+                cout << "Exiting the program.\n";
+                exit(0);
+
+            default:
+                cout << "Invalid choice. Please try again.\n";
+            }
+        }
+    }
+};
+
+int main() {
+    DoubleLinkedList doublyLinkedList;
+    doublyLinkedList.menu();
+
+    return 0;
+}