DeleteNode.java

/* (C) 2024 YourCompanyName */
package linked_list;

/**
 * Created by gouthamvidyapradhan on 04/07/2017. Write a function to delete a node (except the tail)
 * in a singly linked list, given only access to that node.
 *
 * <p>Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3,
 * the linked list should become 1 -> 2 -> 4 after calling your function.
 */
public class DeleteNode {
  public static class ListNode {
    int val;
    ListNode next;

    ListNode(int x) {
      val = x;
    }
  }

  public static void main(String[] args) {
    ListNode node = new ListNode(1);
    node.next = new ListNode(2);
    node.next.next = new ListNode(3);
    node.next.next.next = new ListNode(4);
    new DeleteNode().deleteNode(node.next.next);
    while (node != null) {
      System.out.println(node.val);
      node = node.next;
    }
  }

  public void deleteNode(ListNode node) {
    ListNode prev = node;
    ListNode last = node;
    ListNode next = node.next;
    while (next != null) {
      last = prev;
      int temp = prev.val;
      prev.val = next.val;
      next.val = temp;
      prev = prev.next;
      next = next.next;
    }
    last.next = null;
  }
}