LeetCode/com/zerroi/leetcode/Three26/Partition.java

package com.zerroi.leetcode.Three26;

public class Partition {
    public static void main(String[] args) {
        ListNode head = ListNode.constructLinkedList(new int[]{1, 4, 3, 2, 5, 2});
        SolutionSecond solutionSecond = new SolutionSecond();
        ListNode res = solutionSecond.partition(head, 3);
    }
}

class SolutionSecond {
    public ListNode partition(ListNode head, int x) {
        if (head == null) return null;
        ListNode dummy1 = new ListNode(-1);
        ListNode cur1 = dummy1;
        ListNode dummy2 = new ListNode(-1);
        ListNode cur2 = dummy2;
        while (head != null) {
            if (head.val < x) {
                cur1.next = new ListNode(head.val);
                cur1 = cur1.next;
            } else {
                cur2.next = new ListNode(head.val);
                cur2 = cur2.next;
            }
            head = head.next;
        }
        cur1.next = dummy2.next;

        return dummy1.next;
    }
}