Intersection of linked list

/**
 * Definition for singly-linked list.
 * Definition for singly-linked list.
 * struct ListNode {
 * struct ListNode {
 *     int val;
 *     int val;
 *     ListNode *next;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 * };
 */
 */
class Solution {
public:
    ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {
        ListNode* p1 = headA;
        ListNode* p2 = headB;
        while (p1 != p2) {
            p1 = p1 ? p1->next : headA;
            p2 = p2 ? p2->next : headB;
        }
        return p1;
    }
};