Doubly Linked List: Node Structure and Traversal

Doubly Linked List (DLL) ek two-way linear data structure hai jisme har node ke paas do pointers hote hain: ek previous node ko point karta hai aur doosra next node ko. Isse hum list ko dono directions (Forward aur Backward) me seamlessly traverse kar sakte hain.

DLL Node Structure in C

struct Node {
    int data;
    struct Node* prev;    // Address of previous node
    struct Node* next;    // Address of next node
};

HEAD
 |
 v
NULL <--- [ Prev | 10 | Next ] <===> [ Prev | 20 | Next ] <===> [ Prev | 30 | Next ] ---> NULL

Advantages and Disadvantages of DLL

• Advantage: Bidirectional Traversal: Forward aur backward dono directions me navigate kar sakte hain (e.g. Browser back/forward history, music player playlist).
• Advantage: Efficient Deletion: Agar target node ka pointer pata ho, toh use O(1) time me delete kiya ja sakta hai bina head se traverse kiye.
• Disadvantage: Memory Overhead: Har node me do pointers (8 + 8 = 16 bytes on 64-bit systems) maintain karne padte hain.
• Disadvantage: Complex Pointer Updates: Insertion aur deletion operations me 4 pointers ko manage karna padta hai.

Agli post me hum cover karenge Doubly Linked List: Insertion and Deletion Operations.