package main
import (
	"bufio"
	"log"
	"os"
	"strconv"
	"strings"
)
type packet struct {
	version uint8
	typeID  uint8
	number  uint64
}
type BITS struct {
	packets []packet
}
func main() {
	if err := myMain(); err != nil {
		log.Println(err)
	}
}
func myMain() error {
	in, err := parseInput("input.txt")
	if err != nil {
		return err
	}
	log.Println(solveFirst(in))
	return nil
}
func solveFirst(in []string) int {
	var sum int
	for _, st := range in {
		b := parseBITS(st)
		sum = 0
		for _, p := range b.packets {
			sum += int(p.version)
		}
		// log.Println(sum)
	}
	return sum
}
func parseBITS(in string) BITS {
	b := BITS{}
	for len(in) >= len("VVVTTTAAAAA") {
		in = b.parsePacket(in)
	}
	return b
}
func (b *BITS) parsePacket(in string) string {
	// log.Println("parsePacket:", in)
	p := packet{}
	temp, err := strconv.ParseUint(in[0:3], 2, 8)
	if err != nil {
		panic(err)
	}
	p.version = uint8(temp)
	temp, err = strconv.ParseUint(in[3:6], 2, 8)
	if err != nil {
		panic(err)
	}
	p.typeID = uint8(temp)
	if p.typeID == 4 {
		p.number, in = parseLiteral(in[6:])
	} else {
		in = b.parseOperator(in[6:])
	}
	b.packets = append(b.packets, p)
	return in
}
func (b *BITS) parseOperator(in string) string {
	// log.Println("parseOperator:", in)
	lengthTypeID, err := strconv.ParseUint(in[:1], 2, 8)
	if err != nil {
		panic(err)
	}
	switch lengthTypeID {
	case 0:
		// total, err := strconv.ParseUint(in[1:16], 2, 64)
		// if err != nil {
		// 	panic(err)
		// }
		// log.Println("total length of subpackets:", total)
		in = b.parsePacket(in[16:])
	case 1:
		// log.Println("subpackets:", in[1:12])
		// subpackets, err := strconv.ParseInt(in[1:12], 2, 8)
		// if err != nil {
		// 	panic(err)
		// }
		// log.Println("numer of subpackets", subpackets)
		in = b.parsePacket(in[12:])
	default:
		panic("invalid lengthTypeID")
	}
	return in
}
func parseLiteral(in string) (uint64, string) {
	// log.Println("parseLiteral:", in)
	tmp := strings.Builder{}
	for i := 0; i < len(in); {
		tmp.WriteString(in[i+1 : i+5])
		if in[i] == '0' {
			in = in[i+5:]
			break
		}
		i += 5
	}
	temp, err := strconv.ParseUint(tmp.String(), 2, 64)
	if err != nil {
		panic(err)
	}
	return temp, in
}
func parseInput(fileName string) ([]string, error) {
	ret := []string{}
	fd, err := os.Open(fileName)
	if err != nil {
		return ret, err
	}
	defer fd.Close()
	hexToBin := map[rune]string{
		'0': "0000",
		'1': "0001",
		'2': "0010",
		'3': "0011",
		'4': "0100",
		'5': "0101",
		'6': "0110",
		'7': "0111",
		'8': "1000",
		'9': "1001",
		'A': "1010",
		'B': "1011",
		'C': "1100",
		'D': "1101",
		'E': "1110",
		'F': "1111",
	}
	buf := bufio.NewScanner(fd)
	for buf.Scan() {
		tmp := strings.Builder{}
		for _, ch := range buf.Text() {
			tmp.WriteString(hexToBin[ch])
		}
		ret = append(ret, tmp.String())
	}
	return ret, nil
}

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

D2FE28
38006F45291200
EE00D40C823060
8A004A801A8002F478
620080001611562C8802118E34
C0015000016115A2E0802F182340
A0016C880162017C3686B18A3D4780

module main
go 1.17