【LeetCode】Partition List

/**
* Definition for singly-linked list.
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *partition(ListNode *head, int x) {
ListNode *less = new ListNode(0);
ListNode *more = new ListNode(0);
ListNode *indexLess, *indexMore;
less->next=NULL;
indexLess = less; indexMore = more;
if (head == NULL || head->next == NULL)
return head;
while (head)
{
if (head->val < x)
{
indexLess->next = head;
head = head->next;
indexLess = indexLess->next;
indexLess->next = NULL;
}
else
{
indexMore->next = head;
head = head->next;
indexMore = indexMore->next;
indexMore->next = NULL;
}
}
indexLess->next = more->next;
return less->next;
}
};