// Package q445 implements a solution for https://leetcode.com/problems/add-two-numbers-ii/
package q445

type ListNode struct {
	Val  int
	Next *ListNode
}

func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
	var a1, a2 []*ListNode
	for l1 != nil {
		a1 = append(a1, l1)
		l1 = l1.Next
	}
	for l2 != nil {
		a2 = append(a2, l2)
		l2 = l2.Next
	}

	ret := make([]ListNode, max(len(a1), len(a2))+1)
	for i := range ret {
		if i < len(a1) {
			ret[i].Val += a1[len(a1)-1-i].Val
		}
		if i < len(a2) {
			ret[i].Val += a2[len(a2)-1-i].Val
		}
		if ret[i].Val > 9 {
			ret[i+1].Val += ret[i].Val / 10
			ret[i].Val %= 10
		}

		if i > 0 {
			ret[i].Next = &ret[i-1]
		}
	}

	for i := len(ret) - 1; i >= 0; i-- {
		if ret[i].Val > 0 {
			return &ret[i]
		}
	}
	return &ret[0]
}

var _ = addTwoNumbers