题解 | #两个链表的第一个公共结点#

# class ListNode:
#     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
        """       
        l = []
        if not pHead1 or not pHead2:
            return None
        else:
            while pHead1 != None:
                l.append(pHead1.val)
            while pHead2 != None:
                if pHead2.val in l:
                    break
                else:
                    pHead2 = pHead2.next
        return pHead2
        """ 
        if not pHead1 or not pHead2:
            return None
        else:
            while pHead1:
                p = pHead2
                while p:
                    if p.val == pHead1.val and p.next == pHead1.next:
                        return p
                        break
                    else:
                        p = p.next
                pHead1 = pHead1.next
                
            return None