# def __init__(self, x):
# self.val = x
# self.next = None
#
#
# @param pHead1 ListNode类
# @param pHead2 ListNode类
# @return ListNode类
#
class Solution:
def FindFirstCommonNode(self , pHead1 , pHead2 ):
# write code here
if pHead1 is None or pHead2 is None:
return None
p1 = pHead1
p2 = pHead2
while pHead1 != pHead2: # 为什么不用.val 是因为有可能为空的情况,没有.val属性
if pHead1:
pHead1 = pHead1.next
else:
pHead1 = p2
if pHead2:
pHead2 = pHead2.next
else:
pHead2 = p1
return pHead1