/* struct ListNode { int val; struct ListNode *next; ListNode(int x) : val(x), next(NULL) { } };*/ class Solution { public: ListNode* FindFirstCommonNode( ListNode* pHead1, ListNode* pHead2) { if(!pHead1||!pHead2) { return nullptr; } ListNode * p1,*p2; p1=pHead1; p2 = pHead2; while(p1) { p2 = pHead2...