java_力扣_分隔链表

力扣：https://leetcode.cn/problems/partition-list/description/
题目分隔链表

class Solution {
    public ListNode partition(ListNode head, int x) {
        ListNode lefthead=new ListNode(),lefttail=lefthead,righthead=new ListNode(),righttail=righthead;
        while(head!=null){
            if(head.val<x){
                lefttail.next=new ListNode(head.val);
                lefttail=lefttail.next;
            }
            else{
                righttail.next=new ListNode(head.val);
                righttail=righttail.next;
            }
            head=head.next;
        }
        if(lefthead.next!=null){
            lefttail.next=righthead.next;
            return lefthead.next;
        }
        return righthead.next;
    }
}