码迷,mamicode.com
首页 > 其他好文 > 详细

[Lintcode] Partition List

时间:2015-11-17 12:33:45      阅读:175      评论:0      收藏:0      [点我收藏+]

标签:

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->null and x = 3,
return 1->2->2->4->3->5->null.

 

SOLUTION:

其实就是快速排序嘛,比较简单,按照题意实现就对了,开两个头节点,一个放小于x的,一个放大于x的,再拼起来。

注意,注意,注意,链表的最后一定要指向null,就是右边的链表尾部一定要指向null!!!

代码:

技术分享
/**
 * Definition for ListNode.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int val) {
 *         this.val = val;
 *         this.next = null;
 *     }
 * }
 */ 
public class Solution {
    /**
     * @param head: The first node of linked list.
     * @param x: an integer
     * @return: a ListNode 
     */
    public ListNode partition(ListNode head, int x) {
        if (head == null){
            return head;
        }
        ListNode dummyLeft = new ListNode(0);
        ListNode dummyRight = new ListNode(0);
        ListNode left = dummyLeft;
        ListNode right = dummyRight;
        while (head != null){
            if (head.val < x){
                left.next = head;
                left = left.next;
            } else {
                right.next = head;
                right = right.next;
            }
            head = head.next;
        }
        left.next = dummyRight.next;
        right.next = null;
        return dummyLeft.next;
    }
}
View Code

 

[Lintcode] Partition List

标签:

原文地址:http://www.cnblogs.com/tritritri/p/4971085.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!