/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} headA
* @param {ListNode} headB
* @return {ListNode}
*/
var getIntersectionNode = function (headA, headB) {
let a = headA;
let b = headB;
while (a !== b) {
a = a === null ? headB : a.next;
b = b === null ? headA : b.next;
}
return a;
};