leetcode -- Partition List -- 常见题型重点

https://leetcode.com/problems/partition-list/

“穿针引线”法。 构造两个dummy，然后穿针引线。

参考http://www.cnblogs.com/zuoyuan/p/3783276.html

class Solution(object):    def partition(self, head, x):        """        :type head: ListNode        :type x: int        :rtype: ListNode        """        dummy1, dummy2 = ListNode(0), ListNode(0)        p1, p2 = dummy1,dummy2        p1.next, p2.next = None, None        i = head        while i:            tmp = i.next            if i.val < x:                p1.next = i                p1 = p1.next                p1.next = None            else:                p2.next = i                p2 = p2.next                p2.next = None            i = tmp        p1.next = dummy2.next        return dummy1.next