<h3><a title="题目描述" href="https://leetcode-cn.com/problems/intersection-of-two-linked-lists/">题目描述</a></h3>   <h4>解法1：</h4> <pre class="EnlighterJSRAW" data-enlighter-language="null"># Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def getIntersectionNode(self, headA, headB): """ :type head1, head1: ListNode :rtype: ListNode """ p, q = headA, headB while(p != q): p = p.next if p else headB q = q.next if q else headA return p</pre>   <h4>解法2：</h4> <pre class="EnlighterJSRAW" data-enlighter-language="null"># Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def getIntersectionNode(self, headA, headB): """ :type head1, head1: ListNode :rtype: ListNode """ visited = set() while headA: visited.add(headA) headA = headA.next while headB: if headB in visited: return headB headB = headB.next return None</pre>   #### Note - 解法1是通过“增加”来消除长度差  - 解法2是通过字典实现，效率更高。