【LeetCode】C# 86、Partition List

Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.

You should preserve the original relative order of the nodes in each of the two partitions.

For example,
Given 1->4->3->2->5->2 and x = 3,
return 1->2->2->4->3->5.

题意：给定单链表和整数x，把单链表中小于x的放前面，大于等于的放后面，且每个数原始相对位置不变。
思路：把小的放在dummy1后面，大的放在dummy2后面，之后合并起来就好。

/** * Definition for singly-linked list. * public class ListNode { *     public int val; *     public ListNode next; *     public ListNode(int x) { val = x; } * } */public class Solution {    public ListNode Partition(ListNode head, int x) {        ListNode dummy1 = new ListNode(0), dummy2 = new ListNode(0);         ListNode curr1 = dummy1, curr2 = dummy2;             while (head!=null){            if (head.val<x) {                curr1.next = head;                curr1 = head;            }else {                curr2.next = head;                curr2 = head;            }            head = head.next;        }        curr2.next = null;                curr1.next = dummy2.next;        return dummy1.next;    }}