题目1： 给定两个链表 A: a1,a2,c1,c2,c3 B：b1,b2,b3,b4,c1,c2,c3
在节点c1处相交
class solution:
def getIntersectionNode(self,headA,headB):
a,b = headA,headB
while a != b:
if a:
a = a.next
elif a == None:
a = headB
if b:
b = b.next
elif b == None:
b = headA
return a
题目2： 查找二茶树的最近公共祖先
class solution():
def func(root,p,q):
if not root or root == p or root == q:
return root
left = self.func(root.left,p,q)
right = self.func(root.right,p,q)
if not left and not right:
return
if not left:
return right
if not right:
return left
return root
