237. Delete Node in a Linked List
Easy
Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.
Given linked list -- head = [4,5,1,9], which looks like following:
Example 1:
Input: head = [4,5,1,9], node = 5 Output: [4,1,9] Explanation: You are given the second node with value 5, the linked list should become 4 -> 1 -> 9 after calling your function.
Example 2:
Input: head = [4,5,1,9], node = 1 Output: [4,5,9] Explanation: You are given the third node with value 1, the linked list should become 4 -> 5 -> 9 after calling your function.
Note:
- The linked list will have at least two elements.
- All of the nodes' values will be unique.
- The given node will not be the tail and it will always be a valid node of the linked list.
- Do not return anything from your function.
package leetcode.easy; /** * Definition for singly-linked list. public class ListNode { int val; ListNode * next; ListNode(int x) { val = x; } } */ public class DeleteNodeInALinkedList { private static void print(ListNode head) { if (head == null) { return; } while (head != null) { System.out.print(head.val); if (head.next != null) { System.out.print("->"); } head = head.next; } System.out.println(); } public void deleteNode(ListNode node) { node.val = node.next.val; node.next = node.next.next; } @org.junit.Test public void test1() { ListNode listNode1 = new ListNode(4); ListNode listNode2 = new ListNode(5); ListNode listNode3 = new ListNode(1); ListNode listNode4 = new ListNode(9); listNode1.next = listNode2; listNode2.next = listNode3; listNode3.next = listNode4; listNode4.next = null; print(listNode1); deleteNode(listNode2); print(listNode1); } @org.junit.Test public void test2() { ListNode listNode1 = new ListNode(4); ListNode listNode2 = new ListNode(5); ListNode listNode3 = new ListNode(1); ListNode listNode4 = new ListNode(9); listNode1.next = listNode2; listNode2.next = listNode3; listNode3.next = listNode4; listNode4.next = null; print(listNode1); deleteNode(listNode3); print(listNode1); } }