标签：des style blog class c code
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.
1 /** 2 * Definition for singly-linked list. 3 * struct ListNode { 4 * int val; 5 * ListNode *next; 6 * ListNode(int x) : val(x), next(NULL) {} 7 * }; 8 */ 9 class Solution { 10 public: 11 ListNode * partition(ListNode *head, int x) { 12 ListNode dummy_left(-1), dummy_right(-1); 13 ListNode *pl = &dummy_left, *pr = &dummy_right; 14 for (ListNode * p = head; p != nullptr; p = p->next) { 15 if (p->val < x) { 16 pl->next = p; 17 pl = pl->next; 18 } else { 19 pr->next = p; 20 pr = pr->next; 21 } 22 } 23 pl->next = dummy_right.next; 24 pr->next = nullptr; 25 return dummy_left.next; 26 } 27 };
维护两个链表，一个保存小于x的部分，一个保存大于x的部分，最后将两个链表拼接起来。要求保持稳定性则应该用尾插法。加dummy元素可使代码变简单。
【Leetcode】Partition List,布布扣,bubuko.com
标签：des style blog class c code
原文地址：http://www.cnblogs.com/dengeven/p/3738570.html
