Package g0701_0800.s0707_design_linked_list

Class MyLinkedList

java.lang.Object
g0701_0800.s0707_design_linked_list.MyLinkedList
public class MyLinkedList extends Object
707 - Design Linked List\. Medium Design your implementation of the linked list. You can choose to use a singly or doubly linked list. A node in a singly linked list should have two attributes: `val` and `next`. `val` is the value of the current node, and `next` is a pointer/reference to the next node. If you want to use the doubly linked list, you will need one more attribute `prev` to indicate the previous node in the linked list. Assume all nodes in the linked list are **0-indexed**. Implement the `MyLinkedList` class: * `MyLinkedList()` Initializes the `MyLinkedList` object. * `int get(int index)` Get the value of the indexth node in the linked list. If the index is invalid, return `-1`. * `void addAtHead(int val)` Add a node of value `val` before the first element of the linked list. After the insertion, the new node will be the first node of the linked list. * `void addAtTail(int val)` Append a node of value `val` as the last element of the linked list. * `void addAtIndex(int index, int val)` Add a node of value `val` before the indexth node in the linked list. If `index` equals the length of the linked list, the node will be appended to the end of the linked list. If `index` is greater than the length, the node **will not be inserted**. * `void deleteAtIndex(int index)` Delete the indexth node in the linked list, if the index is valid. **Example 1:** **Input** ["MyLinkedList", "addAtHead", "addAtTail", "addAtIndex", "get", "deleteAtIndex", "get"] [ [], [1], [3], [1, 2], [1], [1], [1]] **Output:** [null, null, null, null, 2, null, 3] **Explanation:** MyLinkedList myLinkedList = new MyLinkedList(); myLinkedList.addAtHead(1); myLinkedList.addAtTail(3); myLinkedList.addAtIndex(1, 2); // linked list becomes 1->2->3 myLinkedList.get(1); // return 2 myLinkedList.deleteAtIndex(1); // now the linked list is 1->3 myLinkedList.get(1); // return 3 **Constraints:** * `0 <= index, val <= 1000` * Please do not use the built-in LinkedList library. * At most `2000` calls will be made to `get`, `addAtHead`, `addAtTail`, `addAtIndex` and `deleteAtIndex`.

  • Constructor Details

    • MyLinkedList

      public MyLinkedList()

  • Method Details

    • get

      public int get(int index)

    • addAtHead

      public void addAtHead(int val)

    • addAtTail

      public void addAtTail(int val)

    • addAtIndex

      public void addAtIndex(int index, int val)

    • deleteAtIndex

      public void deleteAtIndex(int index)