Class MyLinkedList
java.lang.Object
g0701_0800.s0707_design_linked_list.MyLinkedList
public class MyLinkedList
extends java.lang.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 theMyLinkedList
object.int get(int index)
Get the value of theindexth
node in the linked list. If the index is invalid, return-1
.void addAtHead(int val)
Add a node of valueval
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 valueval
as the last element of the linked list.void addAtIndex(int index, int val)
Add a node of valueval
before theindexth
node in the linked list. Ifindex
equals the length of the linked list, the node will be appended to the end of the linked list. Ifindex
is greater than the length, the node will not be inserted.void deleteAtIndex(int index)
Delete theindexth
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 toget
,addAtHead
,addAtTail
,addAtIndex
anddeleteAtIndex
.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
addAtHead
(int val) void
addAtIndex
(int index, int val) void
addAtTail
(int val) void
deleteAtIndex
(int index) int
get
(int index) Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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MyLinkedList
public MyLinkedList()
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Method Details
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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)
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