0086.分隔链表.cs

/*
 * @lc app=leetcode.cn id=86 lang=csharp
 *
 * [86] 分隔链表
 *
 * https://leetcode-cn.com/problems/partition-list/description/
 *
 * algorithms
 * Medium (60.30%)
 * Likes:    354
 * Dislikes: 0
 * Total Accepted:    85.1K
 * Total Submissions: 136.5K
 * Testcase Example:  '[1,4,3,2,5,2]\n3'
 *
 * 给你一个链表和一个特定值 x ，请你对链表进行分隔，使得所有小于 x 的节点都出现在大于或等于 x 的节点之前。
 * 
 * 你应当保留两个分区中每个节点的初始相对位置。
 * 
 * 
 * 
 * 示例：
 * 
 * 
 * 输入：head = 1->4->3->2->5->2, x = 3
 * 输出：1->2->2->4->3->5
 * 
 * 
 */

// @lc code=start
/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     public int val;
 *     public ListNode next;
 *     public ListNode(int val=0, ListNode next=null) {
 *         this.val = val;
 *         this.next = next;
 *     }
 * }
 */
public class Solution {
    public ListNode Partition(ListNode head, int x) {
        ListNode small = new ListNode(0);
        ListNode smallHead = small;
        ListNode large = new ListNode(0);
        ListNode largeHead = large;
        while (head != null) {
            if (head.val < x) {
                small.next = head;
                small = small.next;
            } else {
                large.next = head;
                large = large.next;
            }
            head = head.next;
        }
        large.next = null;
        small.next = largeHead.next;
        return smallHead.next;
    }
}
// @lc code=end