Doubly Linked List Structure and Node Design in DSA C - Build from Scratch

Doubly Linked List Structure and Node Design

📖 Scenario: Imagine you are building a simple music playlist app. Each song is connected to the previous and next song, so you can easily move forward or backward through the playlist.

🎯 Goal: You will create the basic structure of a doubly linked list in C. This includes designing the node that holds each song's data and pointers to the previous and next songs.

📋 What You'll Learn

Define a struct called Node with an integer data field

Include two pointers in Node: prev and next, both pointing to Node

Create a pointer called head to represent the start of the list and initialize it to NULL

💡 Why This Matters

🌍 Real World

Doubly linked lists are used in music players, browsers, and many apps to move forward and backward through items easily.

💼 Career

Understanding linked list structures is fundamental for software developers working with data storage, memory management, and building efficient applications.

1

Create the Node struct

Define a struct called Node that has an integer field named data.

DSA C

// Your code here

Hint

Use typedef struct Node { int data; } Node; to define the node structure.

2

Add prev and next pointers to Node

Add two pointers inside the Node struct: Node *prev and Node *next.

DSA C

typedef struct Node {
    int data;
    // Add prev and next pointers here
} Node;

Hint

Remember to use struct Node * for the pointers inside the struct.

3

Create head pointer for the list

Declare a pointer called head of type Node * and initialize it to NULL.

DSA C

typedef struct Node {
    int data;
    struct Node *prev;
    struct Node *next;
} Node;

// Declare head pointer here

Hint

Use Node *head = NULL; to start with an empty list.

4

Print the initial state of the list

Write a printf statement to print "List head: %p\n" with the head pointer.

DSA C

typedef struct Node {
    int data;
    struct Node *prev;
    struct Node *next;
} Node;

Node *head = NULL;

// Print the head pointer

Hint

Use printf("List head: %p\n", (void *)head); to print the pointer value.