Solution203.java

package LinkedList_problem;


/**
 * 使用虚拟头结点
 * O(n)
 * O(1)
 */
public class Solution203 {

    // Definition for singly-linked list.
    public class ListNode {
        int val;
        ListNode next;

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

    public ListNode removeElements(ListNode head, int val) {

        ListNode dummyHead = new ListNode(0);
        dummyHead.next = head;

        ListNode cur = dummyHead;
        while (cur.next != null) {
            if (cur.next.val == val) {
                ListNode delNode = cur.next;
                cur.next = delNode.next;
            } else {
                cur = cur.next;
            }
        }

        return dummyHead.next;
    }

}