题解 | #牛群分隔# Java

就是新构造两个链子，分别存小于x的和大于等于x的，最后把两个链子合起来

学到的东西：

• 用临时ListNode 存储head的next，用完了再赋值给head
• 注意断开节点之前的链子 防止干扰

public class Solution {

    public ListNode cow_partition (ListNode head, int x) {

        ListNode smallHead = new ListNode(0);
        ListNode smallCur = smallHead;
        ListNode bigHead = new ListNode(0);
        ListNode bigCur = bigHead;
        while (head != null) {
            ListNode tmp = head.next;
            head.next = null; //断开链接
            if (head.val < x) {
                smallCur.next = head;
                smallCur = smallCur.next;
            } else {
                bigCur.next = head;
                bigCur = bigCur.next;
            }
            head = tmp;
        }

        smallCur.next = bigHead.next;
        return smallHead.next;
    }
}