package main

import "leetcode-golang/entity"

// headA = a + c = m
// headB = b + c = n
// a + b + c

// A = a + c + b
// B = b + c + a
func getIntersectionNode(headA, headB *entity.ListNode) *entity.ListNode {

	if headA == nil || headB == nil {
		return nil
	}
	pa, pb := headA, headB
	for pa != pb {
		if pa == nil {
			pa = headB
		} else {
			pa = pa.Next
		}
		if pb == nil {
			pb = headA
		} else {
			pb = pb.Next
		}
	}
	return pa
}