Leetcode203:移除链表元素

删除链表中等于给定值 val 的所有节点。

示例: 输入: 1->2->6->3->4->5->6, val = 6 输出: 1->2->3->4->5

解法1 暴力一趟遍历

public ListNode removeElements(ListNode head, int val) { ListNode dummyHead = new ListNode(-1); dummyHead.next = head; ListNode pre = dummyHead; ListNode cur = dummyHead.next; while (cur != null) { if (cur.val == val) { pre.next = cur.next; cur = cur.next; }else { pre = cur; cur = cur.next; } } return dummyHead.next; }

解法2 递归

public ListNode removeElements2(ListNode head, int val) { if (head == null) { return null; } ListNode node = removeElements2(head.next, val); head.next = node; if (head.val == val) { return node; }else { return head; } }