package top100liked

import (
	"fmt"
	"strings"
	"testing"
	"unicode"
)

// https://leetcode.cn/problems/decode-string/description/?envType=study-plan-v2&envId=top-100-liked

func decodeString(s string) string {
	curStr := ""
	curNum := 0
	strStack := []string{}
	numStack := []int{}
	for _, r := range s {
		if unicode.IsDigit(r) {
			curNum = curNum*10 + int(r-'0')
		} else if unicode.IsLetter(r) {
			curStr += string(r)
		} else if r == '[' {
			strStack = append(strStack, curStr)
			curStr = ""
			numStack = append(numStack, curNum)
			curNum = 0
		} else if r == ']' {
			num := numStack[len(numStack)-1]
			prevStr := strStack[len(strStack)-1]
			numStack = numStack[:len(numStack)-1]
			strStack = strStack[:len(strStack)-1]
			curStr = prevStr + strings.Repeat(curStr, num)
		}
	}
	return curStr
}

func Test(t *testing.T) {
	fmt.Println(decodeString("3[a]2[bc]"))
	fmt.Println(decodeString("3[a2[c]]"))
	fmt.Println(decodeString("2[abc]3[cd]ef"))
	fmt.Println(decodeString("abc3[cd]xyz"))
}