Linked List Implementation in C - Micro Project

Linked List Implementation in C

In this blog post, we will discuss the implementation of a singly linked list using the C programming language.

Linked List Operations

• Create a new node
• Insertion at the beginning of the linked list
• Insertion at the end of the linked list
• Insertion at a specific position in the linked list
• Deletion of a node from the linked list
• Searching for an element in the linked list
• Displaying the elements of the linked list

Code Implementation

#include 
#include 

// Structure for a linked list node
struct Node {
    int data;
    struct Node* next;
};

// Function to create a new node
struct Node* createNode(int data) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}

// Function to insert a node at the beginning of the linked list
void insertAtBeginning(struct Node** head, int data) {
    struct Node* newNode = createNode(data);
    newNode->next = *head;
    *head = newNode;
    printf("Node inserted successfully at the beginning.\n");
}

// Function to insert a node at the end of the linked list
void insertAtEnd(struct Node** head, int data) {
    struct Node* newNode = createNode(data);
    if (*head == NULL) {
        *head = newNode;
        printf("Node inserted successfully at the end.\n");
        return;
    }
    struct Node* temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = newNode;
    printf("Node inserted successfully at the end.\n");
}

// Function to insert a node at a specific position in the linked list
void insertAtPosition(struct Node** head, int data, int position) {
    if (position == 1) {
        insertAtBeginning(head, data);
        return;
    }
    struct Node* newNode = createNode(data);
    struct Node* temp = *head;
    int count = 1;
    while (temp != NULL && count < position - 1) {
        temp = temp->next;
        count++;
    }
    if (temp == NULL) {
        printf("Invalid position.\n");
        return;
    }
    newNode->next = temp->next;
    temp->next = newNode;
    printf("Node inserted successfully at position %d.\n", position);
}

// Function to delete a node from the linked list
void deleteNode(struct Node** head, int key) {
    struct Node* temp = *head;
    struct Node* prev = NULL;
    if (temp != NULL && temp->data == key) {
        *head = temp->next;
        free(temp);
        printf("Node deleted successfully.\n");
        return;
    }
    while (temp != NULL && temp->data != key) {
        prev = temp;
        temp = temp->next;
    }
    if (temp == NULL) {
        printf("Node not found.\n");
        return;
    }
    prev->next = temp->next;
    free(temp);
    printf("Node deleted successfully.\n");
}

// Function to search for an element in the linked list
void searchElement(struct Node* head, int key) {
    struct Node* temp = head;
    int position = 1;
    while (temp != NULL) {
        if (temp->data == key) {
            printf("Element found at position %d.\n", position);
            return;
        }
        temp = temp->next;
        position++;
    }
    printf("Element not found.\n");
}

// Function to display the elements of the linked list
void displayList(struct Node* head) {
    if (head == NULL) {
        printf("Linked list is empty.\n");
        return;
    }
    struct Node* temp = head;
    printf("Linked list elements: ");
    while (temp != NULL) {
        printf("%d ", temp->data);
        temp = temp->next;
    }
    printf("\n");
}

// Function to clear the linked list and free memory
void clearList(struct Node** head) {
    struct Node* temp = *head;
    while (temp != NULL) {
        struct Node* nextNode = temp->next;
        free(temp);
        temp = nextNode;
    }
    *head = NULL;
    printf("Linked list cleared and memory freed.\n");
}

int main() {
    struct Node* head = NULL;
    int choice, data, position, key;
    while (1) {
        printf("\n--- Linked List Implementation ---\n");
        printf("1. Insert at the beginning\n");
        printf("2. Insert at the end\n");
        printf("3. Insert at a position\n");
        printf("4. Delete a node\n");
        printf("5. Search for an element\n");
        printf("6. Display the linked list\n");
        printf("7. Clear the linked list\n");
        printf("8. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter the element to insert: ");
                scanf("%d", &data);
                insertAtBeginning(&head, data);
                break;
            case 2:
                printf("Enter the element to insert: ");
                scanf("%d", &data);
                insertAtEnd(&head, data);
                break;
            case 3:
                printf("Enter the element to insert: ");
                scanf("%d", &data);
                printf("Enter the position: ");
                scanf("%d", &position);
                insertAtPosition(&head, data, position);
                break;
            case 4:
                printf("Enter the element to delete: ");
                scanf("%d", &key);
                deleteNode(&head, key);
                break;
            case 5:
                printf("Enter the element to search: ");
                scanf("%d", &key);
                searchElement(head, key);
                break;
            case 6:
                displayList(head);
                break;
            case 7:
                clearList(&head);
                break;
            case 8:
                exit(0);
            default:
                printf("Invalid choice. Please try again.\n");
        }
    }
    return 0;
}

        

Output

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 1
Enter the element to insert: 5
Node inserted successfully at the beginning.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 2
Enter the element to insert: 10
Node inserted successfully at the end.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 3
Enter the element to insert: 7
Enter the position: 2
Node inserted successfully at position 2.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 6
Linked list elements: 5 7 10

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 4
Enter the element to delete: 7
Node deleted successfully.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 5
Enter the element to search: 10
Element found at position 2.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 7
Linked list cleared and memory freed.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 6
Linked list is empty.

--- Linked List Implementation ---
1. Insert at the beginning
2. Insert at the end
3. Insert at a position
4. Delete a node
5. Search for an element
6. Display the linked list
7. Clear the linked list
8. Exit
Enter your choice: 8
        

Conclusion

In this blog post, we have covered the implementation of a linked list in C. Linked lists are fundamental data structures that allow efficient insertion and deletion operations. By understanding and implementing linked lists, you will gain a solid foundation for further exploration of data structures and algorithms.