Java MCQ: In which scenario is the Linked List an excellent data structure?
Answer:
Explanation:
A Linked List is an excellent data structure when you need to insert elements in the middle of the list. Unlike arrays, which require shifting elements to make space for new entries, linked lists allow for efficient insertion and deletion at any position in the list. This is because each node in a linked list contains a reference to the next node, so inserting a new node only involves updating a few pointers.
For example, to insert a new node between two existing nodes in a singly linked list, you simply adjust the next pointer of the previous node to point to the new node, and then set the new node’s next pointer to the node that originally followed the previous node. This operation is done in constant time, O(1), regardless of the size of the list:
public void insertAfter(Node prevNode, int newData) {
if (prevNode == null) {
System.out.println("Previous node cannot be null");
return;
}
Node newNode = new Node(newData);
newNode.next = prevNode.next;
prevNode.next = newNode;
}
This makes linked lists particularly useful in scenarios where frequent insertions and deletions are required, such as in dynamic data structures like queues, stacks, and deques. However, if you need quick access to elements by index, arrays are more suitable because they offer O(1) time complexity for element access, whereas linked lists require O(n) time to traverse the list to find an element.