题解 | #两个链表的第一个公共结点#

/*
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*>  visited;
		while(pHead1)
		{
			visited.insert(pHead1);
			pHead1=pHead1->next;
		}
		while(pHead2)
		{
			if(visited.count(pHead2))
				return pHead2;
			pHead2=pHead2->next;
		}
		return nullptr;
    }
};