打卡群刷题总结0729——分隔链表

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def partition(self, head, x):
        """
        :type head: ListNode
        :type x: int
        :rtype: ListNode
        """
        head1 = ListNode(0)
        head2 = ListNode(0)
        p = head1
        q = head2
        
        cur = head
        while cur:
            if cur.val < x:
                p.next = cur
                p = p.next
            else:
                q.next = cur
                q = q.next
            cur = cur.next
        p.next = head2.next
        q.next = None
        return head1.next