Design your implementation of the linked list. You can choose to use the singly linked list or the doubly linked list. A node in a singly linked list should have two attributes:
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 these functions in your linked list class:
- get(index) : Get the value of the
index-th node in the linked list. If the index is invalid, return
- addAtHead(val) : Add a node of value
valbefore the first element of the linked list. After the insertion, the new node will be the first node of the linked list.
- addAtTail(val) : Append a node of value
valto the last element of the linked list.
- addAtIndex(index, val) : Add a node of value
index-th node in the linked list. If
indexequals to the length of linked list, the node will be appended to the end of linked list. If index is greater than the length, the node will not be inserted.
- deleteAtIndex(index) : Delete the
index-th node in the linked list, if the index is valid.
MyLinkedList linkedList = new MyLinkedList();
- All values will be in the range of
- The number of operations will be in the range of
- Please do not use the built-in LinkedList library.