Singly Linked List | Visualize 3D

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Speed

🔗 Singly Linked List

A linear data structure where elements are stored in nodes. Each node contains data and a pointer (next) to the next node in the sequence.

⏱ Access: O(n) ⏱ Search: O(n) ⏱ Insertion: O(1)* ⏱ Deletion: O(1)*

*O(1) if you have a reference to the node, otherwise O(n) to find it.

Python

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

    def insert_at_head(self, data):
        new_node = Node(data)
        new_node.next = self.head
        self.head = new_node

    def delete_node(self, key):
        temp = self.head
        if temp and temp.data == key:
            self.head = temp.next
            return
        prev = None
        while temp and temp.data != key:
            prev = temp
            temp = temp.next
        if temp:
            prev.next = temp.next

JavaScript

class Node {
    constructor(data) {
        this.data = data;
        this.next = null;
    }
}

class LinkedList {
    constructor() {
        this.head = null;
    }

    insertAtHead(data) {
        const newNode = new Node(data);
        newNode.next = this.head;
        this.head = newNode;
    }

    deleteNode(key) {
        let temp = this.head, prev = null;
        if (temp && temp.data === key) {
            this.head = temp.next;
            return;
        }
        while (temp && temp.data !== key) {
            prev = temp;
            temp = temp.next;
        }
        if (temp) prev.next = temp.next;
    }
}