Singly Linked List in C: Operations, Pros/Cons & Real-World Uses

A singly linked list is a linear data structure where each element (node) contains data and a pointer to the next node. Unlike arrays, nodes aren’t stored contiguously in memory, enabling dynamic memory usage and efficient insertions/deletions.

💡 Real-world analogy: Think of a treasure hunt where each clue points to the next location.

Node Structure Explained

struct node { int data // Data (int, char, etc.) struct node* next; // Pointer to next node };

• data: Actual value (int, char, struct, etc.)
• next: Memory address of next node (or NULL for last node)
• head: Pointer to first node (entry point)

Key Advantages & Disadvantages

💡 Key Insight: Use linked lists when you need frequent insertions/deletions, dynamic sizing, or memory efficiency. Avoid them for random access tasks (e.g., binary search).

Singly Linked List – Core operations in C

1. Create a Node

struct node* createNode(int data) { struct Node* newNode = (struct node*) malloc(sizeof(struct node)); newNode->data = data; newNode->next = NULL; return newNode; }

2. Insert at Head – O(1)

void insertFront(struct node** head, int data) { struct node* newNode = createNode(data); newNode->next = *head; *head = newNode; }

3. Insert at End – O(n)

void insertEnd(struct node** head, int data) { struct node* newNode = createNode(data); if (*head == NULL) { // List is empty *head = newNode; } else { struct node* temp = *head; // Traverse till end of list while (temp->next != NULL) temp = temp->next; temp->next = newNode; } }

4. Delete First Node – O(1)

void deleteFront(struct node** head) { if (*head == NULL) { // List is empty, nothing to delete return; } struct node* temp = *head; *head = (*head)->next; free(temp); }

5. Traverse List

void printList(struct node* head) { while (head != NULL) { printf("%d → ", head->data); head = head->next; } printf("\n"); }

Real-World Applications

• Undo/Redo: Stores editor states in text processors
• Hash Tables: Handles collisions using chaining
• Polynomial Representation: Stores coefficients and exponents

Singly vs. Doubly Linked Lists

🙇‍♂️ Doubly linked list: Pros/cons, applications, implementation.
🙇‍♂️ Arrays vs. Linked Lists