Partition List

最新推荐文章于 2021-04-06 09:37:45 发布

最新推荐文章于 2021-04-06 09:37:45 发布 · 63 阅读

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本文介绍了一种链表分区算法，该算法将链表中小于给定值 x 的节点置于大于等于 x 的节点之前，同时保持各分区内的相对顺序不变。通过实例演示了如何实现这一功能。

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.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    public ListNode partition(ListNode head, int x) {
        if (head==null || head.next==null) {
        	return head;
        }
        ListNode small = new ListNode(-1);
        ListNode big = new ListNode(-1);
        ListNode samllH = small;
        ListNode bigH = big;
        while (head != null) {
        	if (head.val < x) {
        		small.next = head;
        		small = small.next;
        	} else {
        		big.next = head;
        		big = big.next;
        	}
        	head = head.next;
        }
        big.next = null;
        small.next = bigH.next;
        return samllH.next;
    }
}