160相交链表

class Solution {
public:
    ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {
        ListNode* p = headA;
        ListNode* q = headB;
        for (p = headA; p != NULL; p = p->next) {
            for (q = headB; q != NULL; q = q->next) {
                if (p == q) return p;
            }
        }
        return NULL;
    }
};