牛客 寻找两个链表的公共结点

class Solution {
public:
    ListNode* FindFirstCommonNode( ListNode* pHead1,ListNode* pHead2) {
         ListNode* p1=pHead1;
         ListNode* p2=pHead2;
        while(p1!=p2)
            {
              p1=(p1==NULL?pHead2:p1->next);
              p2=(p2==NULL?pHead1:p2->next);
        }
      return p1;
    }
   
};