LeetCode160. 相交链表

class Solution {
public:
    ListNode* getIntersectionNode(ListNode* headA, ListNode* headB) {
        ListNode* pa = headA;
        ListNode* pb = headB;

        while (pa != pb)
        {
            pa = pa == NULL ? headB : pa->next;
            pb = pb == NULL ? headA : pb->next;
        }

        return pa;
    }
};