利用哈希表set()判断节点是否出现过 struct ListNode { int val; struct ListNode *next; ListNode(int x) : val(x), next(NULL) { } };*/ class Solution { public: ListNode* FindFirstCommonNode( ListNode* pHead1, ListNode* pHead2) { unordered_set<ListNode*> pH; ListNode *cur = pHead1; ...