160. Intersection of Two Linked Lists

ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {    int na = 0, nb = 0;    ListNode *headAA = headA;    ListNode *headBB = headB;    while (headAA) {        headAA = headAA->next;        na++;    }    while (headBB) {        headBB = headBB->next;        nb++;    }    int n = na -nb;    if (na > nb) {        while (n--) {            headA = headA->next;        }    }    else if(nb>na){        n = -n;        while (n--) {            headB = headB->next;        }    }    while (headA != headB) {        headA = headA->next;        headB = headB->next;    }    return headA;}