203. Remove Linked List Elements
Remove all elements from a linked list of integers that have value val.
Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> 5
本题比较简单,构造一个dummy头即可。
移位删除时,存在与不存在的删除办法不同
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ public class Solution { public ListNode removeElements(ListNode head, int val) { if (head == null) return head; ListNode dummy = new ListNode(0); dummy.next = head; ListNode prev = dummy; ListNode curr = dummy.next; while(curr.next != null) { if(curr.val == val) { prev.next = curr.next; curr = curr.next; } else { prev = prev.next; curr = curr.next; } } if(curr.next == null) { if(curr.val == val) prev.next = null; } return dummy.next; } }