Sum Root to Leaf Numbers Solutions in Go

package leetcode

import (
	"strconv"
)

import (
	"github.com/halfrost/LeetCode-Go/structures"
)

// TreeNode define
type TreeNode = structures.TreeNode

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */

func sumNumbers(root *TreeNode) int {
	res, nums := 0, binaryTreeNums(root)
	for _, n := range nums {
		num, _ := strconv.Atoi(n)
		res += num
	}
	return res
}

func binaryTreeNums(root *TreeNode) []string {
	if root == nil {
		return []string{}
	}
	res := []string{}
	if root.Left == nil && root.Right == nil {
		return []string{strconv.Itoa(root.Val)}
	}
	tmpLeft := binaryTreeNums(root.Left)
	for i := 0; i < len(tmpLeft); i++ {
		res = append(res, strconv.Itoa(root.Val)+tmpLeft[i])
	}
	tmpRight := binaryTreeNums(root.Right)
	for i := 0; i < len(tmpRight); i++ {
		res = append(res, strconv.Itoa(root.Val)+tmpRight[i])
	}
	return res
}