237. Delete Node in a Linked List

The Singly-Linked List Conundrum

Before delving into the intricacies of the Java solution, let’s understand the problem at hand. In a singly-linked list, each node contains a value and a reference to the next node in the sequence. The task is to delete a given node without access to the head of the linked list.

Unveiling the Java Solution

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public void deleteNode(ListNode node) {
        ListNode temp = node;
        ListNode prev = node;
        while (temp.next != null) {
            temp.val = temp.next.val;
            prev = temp;
            temp = temp.next;
        }
        prev.next = null;
    }
}

Navigating the Code

  1. Traversal Setup:
    • The method deleteNode begins by initializing two pointers, temp and prev, both pointing to the given node.
  2. Value Replacement Loop:
    • A while loop traverses the linked list until the last node is reached (temp.next != null).
    • Inside the loop, the value of the current node (temp.val) is replaced with the value of the next node (temp.next.val).
    • The prev pointer is updated to the current temp position, preparing for the next iteration.
    • The temp pointer moves to the next node.
  3. Breaking the Chain:
    • Once the loop completes, the last node’s value has been copied to its previous node.
    • The prev.next pointer is set to null, effectively breaking the chain and deleting the last node.=

Problem Statement: https://leetcode.com/problems/delete-node-in-a-linked-list/description/

The Essence of the Solution

The brilliance of this Java solution lies in its simplicity and efficiency. By intelligently copying values and breaking the chain at the appropriate moment, the deleteNode method achieves the desired node deletion without compromising the integrity of the linked list.

Conclusion

As we conclude our exploration of the deleteNode method in the Solution class, we’ve witnessed the finesse required to navigate the intricacies of linked list manipulation. Deleting a node might seem straightforward, but this Java solution exemplifies the delicate balance between copying values and preserving the structure of a singly-linked list. As you embark on your coding endeavors, may this exploration serve as a guide in mastering the art of deleting nodes in the captivating world of linked lists.

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