package main

import (
	"fmt"
	"os"
)

func main(){
	PathCheck("D:/11")
}

type TreeNode struct {
	    Val int
	    Left *TreeNode
	    Right *TreeNode
}

func convertBST(root *TreeNode) *TreeNode {
	node := root
	stack := []*TreeNode{}
	sum := 0
	for node != nil || len(stack)>0 {
		for node != nil {
			stack = append(stack,node)
			node = node.Right
		}

		tem := stack[len(stack)-1]
		stack = stack[:len(stack)-1]
		sum += tem.Val
		tem.Val = sum
		node = tem.Left
	}
	return root
}

func PathCheck(path string){
	b,err :=PathExists(path)
	if  err != nil {
		fmt.Println("exist err",err)
	}
	if !b{
		fmt.Println("不存在目录，重新创建")
		err = os.Mkdir("D:/11/", 0777)
		if  err != nil {
			fmt.Println("Mkdir err",err)
		}
	}
}

func PathExists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return false, err
}