标签：des style blog http color io
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,
Given1->4->3->2->5->2and x = 3,
return1->2->2->4->3->5.
算法思路：
维护两个指针，一个指向带插入位置的前驱，一个顺序遍历list，遇到>=x的节点，next，遇到<x的就把它插入到上一个指针的后面。第一个节点<x时候，需要特殊处理
1 public class Solution { 2 public ListNode partition(ListNode head, int x) { 3 if (head == null || head.next == null) return head; 4 ListNode hhead = new ListNode(0); 5 hhead.next = head; 6 ListNode pre = hhead; 7 ListNode tail = hhead; 8 while (tail.next != null) { 9 if (tail.next.val < x) {//第一个节点特殊处理 10 if(tail == hhead){ 11 pre = pre.next; 12 tail = tail.next; 13 continue; 14 } 15 ListNode tem = tail.next; 16 tail.next = tem.next; 17 tem.next = pre.next; 18 pre.next = tem; 19 pre = pre.next; 20 if(tail.val < x){ 21 tail = tail.next; 22 } 23 } else 24 tail = tail.next; 25 } 26 return hhead.next; 27 } 28 }
感觉这道题做的很垃圾。。。。
[leetcode]Partition List,布布扣,bubuko.com
标签：des style blog http color io
原文地址：http://www.cnblogs.com/huntfor/p/3856410.html
