package main

import (
	"fmt"
)

type ListNode struct {
	Val int
	Next *ListNode
}

func (l *ListNode) Print() {
	var tmp *ListNode = l

	for tmp != nil {
		fmt.Printf("%v", tmp.Val)
		tmp = tmp.Next
	}
	fmt.Printf("\n")
}

func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
	var l1Tmp *ListNode = l1
	var l2Tmp *ListNode = l2
	var ret *ListNode = &ListNode{-1, nil}
	var retTail *ListNode = ret
	var buf int = 0

	for l1Tmp != nil && l2Tmp != nil {
		retTail.Val = l1Tmp.Val + l2Tmp.Val

		if buf != 0 {
			retTail.Val += buf
		}
		buf = retTail.Val / 10
		retTail.Val %= 10

		l1Tmp = l1Tmp.Next
		l2Tmp = l2Tmp.Next

		if l1Tmp != nil || l2Tmp != nil {
			retTail.Next = &ListNode{-1, nil}
			retTail = retTail.Next
		}
	}

	for l1Tmp != nil {
		retTail.Val = l1Tmp.Val

		if buf != 0 {
			retTail.Val += buf
			buf = retTail.Val / 10
			retTail.Val %= 10
		}

		l1Tmp = l1Tmp.Next

		if l1Tmp != nil {
			retTail.Next = &ListNode{-1, nil}
			retTail = retTail.Next
		}
	}

	for l2Tmp != nil {
		if retTail == nil {
			retTail = &ListNode{-1, nil}
		}
		retTail.Val = l2Tmp.Val

		if buf != 0 {
			retTail.Val += buf
			buf = retTail.Val / 10
			retTail.Val %= 10
		}

		l2Tmp = l2Tmp.Next

		if l2Tmp != nil {
			retTail.Next = &ListNode{-1, nil}
			retTail = retTail.Next
		}
	}

	if buf != 0 {
		retTail.Next = &ListNode{buf, nil}
		retTail = retTail.Next
	}

	return ret
}

func arrayToListNode(l []int) *ListNode {
	var i int = 0
	var res ListNode = ListNode{l[i], nil}
	var tmp *ListNode = &res
	i++

	for ; i < len(l); i++ {
		tmp.Next = &ListNode{l[i], nil}
		tmp = tmp.Next
	}

	return &res
}

func main() {
	// tmp11 := ListNode{3, nil}
	// tmp12 := ListNode{4, &tmp11}
	// var l1 ListNode = ListNode{2, &tmp12}
	var l1 *ListNode = arrayToListNode([]int{0})
	fmt.Printf("l1 => ")
	l1.Print()

	var l2 *ListNode = arrayToListNode([]int{2, 7, 8})
	fmt.Printf("l2 => ")
	l2.Print()

	// fmt.Printf("res => ")
	addTwoNumbers(l1, l2).Print()
}