package main

import (
	"fmt"
)

func main() {
	a := "123456"
	b := true

	fmt.Println(s(a, b))
}

func s(origin string, b bool) (result []rune) {
	data := []rune(origin)
	dataLen := len(origin)

	resultLen := (dataLen / 4) + 1
	if b {
		result = make([]rune, resultLen+1)
		result[resultLen] = rune(resultLen)
	} else {
		result = make([]rune, resultLen)
	}

	for i := 0; i < dataLen; i += 4 {
		result[i>>2] =
			getCharAt(data, i, dataLen) | getCharAt(data, i+1, dataLen)<<8 | getCharAt(data, i+2, dataLen)<<16 |
				getCharAt(data, i+3, dataLen)<<24
	}

	return result
}

func getCharAt(str []rune, index int, length int) rune {
	if index >= length {
		return 0
	} else {
		return str[index]
	}
}