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import java.util.*
import kotlin.collections.HashMap
object Main {
@JvmStatic
fun main(args: Array<String>) {
val key = "aoada"
val text = "12345"
val enc = text.encrypt(key)
println("密钥为 ${key.genKey().joinToString("")}")
println("明文 -> $text, 加密后 -> ${text.encrypt(key)}")
println("密文 -> $enc, 解密后 -> ${enc.decrypt(key)}")
}
private data class EncryptList(val id: Char, val list: List<Char>)
private fun String.genKey(): MutableList<Char> {
val res = LinkedList<Char>()
this.forEach { el ->
if (!el.isLetterOrDigit()) {
throw IllegalArgumentException("密钥必须为数字或字母")
}
var t = el.uppercaseChar()
var digitCount = 0
var letterCount = 0
// 如果 密钥队列里已经存在当前字符了，那就对下一个字符进行处理
// 尝试顺移
while (res.contains(t)) {
when {
t.isDigit() -> {
t += 1
digitCount++
if (t > '9') {
t = '0'
}
if (digitCount > 10) {
throw IllegalArgumentException("密钥中的数字过多！")
}
}
t.isLetter() -> {
t += 1
letterCount++
if (t > 'Z') {
t = 'A'
}
if (letterCount > 26) {
throw IllegalArgumentException("密钥中的字母过多！")
}
}
}
}
res.add(t)
}
return res
}
private fun String.genPlainText(): MutableList<Char> {
val res = LinkedList<Char>()
this.forEach {
if (it != ' ') {
res.add(it)
}
}
return res
}
private fun List<EncryptList>.genEncrypt(): String {
val res = StringBuilder()
this.sortedBy { it.id }.forEach {
res.append(it.list.joinToString(""))
}
return res.toString()
}
private fun List<EncryptList>.genDecrypt(key: String): String {
val res = StringBuilder()
var column = 0
val xSize = this.size
while (column <= xSize) {
key.genKey().forEach {
this.forEach { el ->
if (it == el.id && el.list.size > column) {
res.append(el.list[column])
}
}
}
column++
}
return res.toString()
}
private fun String.encrypt(key: String): String {
val keyArray = key.genKey()
val textArray = this.genPlainText()
val keySize = keyArray.size
val textSize = textArray.size
val res = LinkedList<EncryptList>()
for (i in 0 until keySize) {
val list = LinkedList<Char>()
var j = i
do {
runCatching {
list.add(textArray[j])
}.onFailure {
it.printStackTrace()
throw IllegalArgumentException("密钥过长或明文过短，请尝试缩短密钥位数或增加明文长度！")
}
j += keySize
} while (j < textSize)
res.add(EncryptList(keyArray[i], list))
}
return res.genEncrypt()
}
private fun String.decrypt(key: String): String {
val keyArray = key.genKey()
val textArray = this.genPlainText()
val keySize = keyArray.size
val textSize = textArray.size
val res = LinkedList<EncryptList>()
var outNum = textSize.mod(keySize)
val row = textSize.div(keySize)
val keyMap = HashMap<Char, Int>()
keyArray.forEach {
var num = row
if (outNum > 0) {
num = row + 1
outNum--
}
keyMap[it] = num
}
println(keyMap)
keyMap.forEach { kMap ->
val keyPlain = LinkedList<Char>()
for (i in outNum until outNum + kMap.value) {
runCatching {
keyPlain.add(textArray[i])
}.onFailure {
it.printStackTrace()
throw IllegalArgumentException("密钥过长或明文过短，请尝试缩短密钥位数或增加明文长度！")
}
}
outNum += kMap.value
res.add(EncryptList(kMap.key, keyPlain))
}
return res.genDecrypt(key)
}
}
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