Linked List — Core Operations

The most important core operations for each type of linked list include:

• Insert (at beginning, end, middle)
• Delete (from beginning, end, specific node)
• Display / Traverse
• Empty check
• Other useful operations like search, count, and reverse

1. Singly Linked List (SLL)

A. Structure

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

B. Core Operations

1. Insert at Beginning

void insertAtHead(struct Node** head, int val) {
    struct Node* newNode = malloc(sizeof(struct Node));
    newNode->data = val;
    newNode->next = *head;
    *head = newNode;
}

2. Insert at End

void insertAtEnd(struct Node** head, int val) {
    struct Node* newNode = malloc(sizeof(struct Node));
    newNode->data = val;
    newNode->next = NULL;
    if (*head == NULL) {
        *head = newNode;
        return;
    }
    struct Node* temp = *head;
    while (temp->next) temp = temp->next;
    temp->next = newNode;
}

3. Delete from Beginning

void deleteFromHead(struct Node** head) {
    if (*head == NULL) return;
    struct Node* temp = *head;
    *head = (*head)->next;
    free(temp);
}

4. Display