LeetCode

package JavaLearning;

//删除链表中等于给定值 val 的所有节点


class Solution_203 {
    public ListNode removeElements(ListNode head, int val) {
        while (head != null && head.val == val) {
            head = head.next;
        }
        // 已经为null，提前退出
        if (head == null) {
            return head;
        }
        // 已确定当前head.val != val
        ListNode pre = head;
        ListNode cur = head.next;
        while (cur != null) {
            if (cur.val == val) {
                pre.next = cur.next;
            } else {
                pre = cur;
            }
            cur = cur.next;
        }
        return head;
    }

}

public class removeElements{
    public static void main(String[] args) {
        Solution_203 remove = new Solution_203();
        ListNode listNode = new ListNode(-1);
        listNode.add(1);
        listNode.add(2);
        listNode.add(6);
        listNode.add(3);
        listNode.add(6);
        listNode.add(4);

        listNode.print();
        System.out.println();
        remove.removeElements(listNode,6);
        listNode.print();
    }
}