[Question]: Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at all, return null.
func getIntersectionNode(_ headA: ListNode?, _ headB: ListNode?) -> ListNode? {
if headA == nil || headB == nil { return nil }
var a = headA, b = headB
// Where a & b node has same reference means it's a intersaction point
while a !== b {
a = a == nil ? headB : a?.next
b = b == nil ? headA : b?.next
// print("Dry run Value of a--", a, " Value of b ---", b)
}
// print("a", a, "b", b)
return a
}