package com.example.firstapp.utils
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import android.graphics.Color
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import android.text.TextUtils
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import java.util.*
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/**
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* <pre>
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* desc : Random Utils
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* author : xuexiang
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* time : 2018/4/28 上午12:41
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</pre> *
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*
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* Shuffling algorithm
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* * [.shuffle] Shuffling algorithm, Randomly permutes the specified array using a default source of
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* randomness
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* * [.shuffle] Shuffling algorithm, Randomly permutes the specified array
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* * [.shuffle] Shuffling algorithm, Randomly permutes the specified int array using a default source of
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* randomness
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* * [.shuffle] Shuffling algorithm, Randomly permutes the specified int array
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*
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*
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* get random int
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* * [.getRandom] get random int between 0 and max
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* * [.getRandom] get random int between min and max
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*
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*
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* get random numbers or letters
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* * [.getRandomCapitalLetters] get a fixed-length random string, its a mixture of uppercase letters
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* * [.getRandomLetters] get a fixed-length random string, its a mixture of uppercase and lowercase letters
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*
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* * [.getRandomLowerCaseLetters] get a fixed-length random string, its a mixture of lowercase letters
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* * [.getRandomNumbers] get a fixed-length random string, its a mixture of numbers
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* * [.getRandomNumbersAndLetters] get a fixed-length random string, its a mixture of uppercase, lowercase
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* letters and numbers
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* * [.getRandom] get a fixed-length random string, its a mixture of chars in source
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* * [.getRandom] get a fixed-length random string, its a mixture of chars in sourceChar
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*
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*
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*/
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@Suppress("MemberVisibilityCanBePrivate", "unused")
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class RandomUtils private constructor() {
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companion object {
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private const val NUMBERS_AND_LETTERS =
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"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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private const val NUMBERS = "0123456789"
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private const val LETTERS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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private const val CAPITAL_LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
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private const val LOWER_CASE_LETTERS = "abcdefghijklmnopqrstuvwxyz"
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/**
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* 在数字和英文字母中获取一个定长的随机字符串
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*
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* @param length 长度
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* @return 随机字符串
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* @see RandomUtils.getRandom
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*/
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@JvmStatic
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fun getRandomNumbersAndLetters(length: Int): String? {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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com.example.firstapp.utils.RandomUtils.Companion.NUMBERS_AND_LETTERS,
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length
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)
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}
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/**
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* 在数字中获取一个定长的随机字符串
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*
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* @param length 长度
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* @return 随机数字符串
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* @see RandomUtils.getRandom
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*/
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fun getRandomNumbers(length: Int): String? {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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com.example.firstapp.utils.RandomUtils.Companion.NUMBERS,
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length
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)
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}
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/**
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* 在英文字母中获取一个定长的随机字符串
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*
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* @param length 长度
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* @return 随机字母字符串
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* @see RandomUtils.getRandom
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*/
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fun getRandomLetters(length: Int): String? {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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com.example.firstapp.utils.RandomUtils.Companion.LETTERS,
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length
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)
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}
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/**
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* 在大写英文字母中获取一个定长的随机字符串
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*
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* @param length 长度
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* @return 随机字符串 只包含大写字母
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* @see RandomUtils.getRandom
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*/
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fun getRandomCapitalLetters(length: Int): String? {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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com.example.firstapp.utils.RandomUtils.Companion.CAPITAL_LETTERS,
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length
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)
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}
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/**
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* 在小写英文字母中获取一个定长的随机字符串
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*
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* @param length 长度
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* @return 随机字符串 只包含小写字母
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* @see RandomUtils.getRandom
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*/
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fun getRandomLowerCaseLetters(length: Int): String? {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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com.example.firstapp.utils.RandomUtils.Companion.LOWER_CASE_LETTERS,
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length
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)
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}
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/**
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* 在一个字符数组源中获取一个定长的随机字符串
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*
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* @param source 源字符串
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* @param length 长度
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* @return
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* * if source is null or empty, return null
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* * else see [RandomUtils.getRandom]
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*
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*/
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fun getRandom(source: String, length: Int): String? {
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return if (TextUtils.isEmpty(source)) null else com.example.firstapp.utils.RandomUtils.Companion.getRandom(
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source.toCharArray(),
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length
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)
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}
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/**
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* 在一个字符数组源中获取一个定长的随机字符串
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*
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* @param sourceChar 字符数组源
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* @param length 长度
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* @return
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* * if sourceChar is null or empty, return null
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* * if length less than 0, return null
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*
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*/
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fun getRandom(sourceChar: CharArray?, length: Int): String? {
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if (sourceChar == null || sourceChar.isEmpty() || length < 0) {
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return null
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}
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val str = StringBuilder(length)
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val random = Random()
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for (i in 0 until length) {
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str.append(sourceChar[random.nextInt(sourceChar.size)])
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}
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return str.toString()
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}
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/**
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* get random int between 0 and max
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*
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* @param max 最大随机数
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* @return
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* * if max <= 0, return 0
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* * else return random int between 0 and max
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*
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*/
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fun getRandom(max: Int): Int {
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return com.example.firstapp.utils.RandomUtils.Companion.getRandom(0, max)
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}
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/**
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* get random int between min and max
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*
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* @param min 最小随机数
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* @param max 最大随机数
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* @return
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* * if min > max, return 0
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* * if min == max, return min
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* * else return random int between min and max
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*
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*/
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fun getRandom(min: Int, max: Int): Int {
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if (min > max) {
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return 0
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}
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return if (min == max) {
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min
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} else min + Random().nextInt(max - min)
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}
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/**
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* 获取随机颜色
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*
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* @return
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*/
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val randomColor: Int
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get() {
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val random = Random()
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val r = random.nextInt(256)
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val g = random.nextInt(256)
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val b = random.nextInt(256)
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return Color.rgb(r, g, b)
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}
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/**
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* 随机打乱数组中的内容
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*
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* @param objArray
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* @return
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*/
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fun shuffle(objArray: Array<Any?>?): Boolean {
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return if (objArray == null) {
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false
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} else com.example.firstapp.utils.RandomUtils.Companion.shuffle(
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objArray,
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com.example.firstapp.utils.RandomUtils.Companion.getRandom(objArray.size)
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)
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}
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/**
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* 随机打乱数组中的内容
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*
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* @param objArray
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* @param shuffleCount
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* @return
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*/
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private fun shuffle(objArray: Array<Any?>?, shuffleCount: Int): Boolean {
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var length = 0
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if (objArray == null || shuffleCount < 0 || objArray.size.also {
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length = it
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} < shuffleCount) {
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return false
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}
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for (i in 1..shuffleCount) {
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val random = com.example.firstapp.utils.RandomUtils.Companion.getRandom(length - i)
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val temp = objArray[length - i]
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objArray[length - i] = objArray[random]
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objArray[random] = temp
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}
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return true
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}
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/**
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* 随机打乱数组中的内容
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*
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* @param intArray
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* @return
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*/
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fun shuffle(intArray: IntArray?): IntArray? {
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return if (intArray == null) {
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null
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} else com.example.firstapp.utils.RandomUtils.Companion.shuffle(
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intArray,
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com.example.firstapp.utils.RandomUtils.Companion.getRandom(intArray.size)
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)
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}
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/**
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* 随机打乱数组中的内容
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*
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* @param intArray
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* @param shuffleCount
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* @return
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*/
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fun shuffle(intArray: IntArray?, shuffleCount: Int): IntArray? {
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var length = 0
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if (intArray == null || shuffleCount < 0 || intArray.size.also {
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length = it
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} < shuffleCount) {
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return null
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}
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val out = IntArray(shuffleCount)
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for (i in 1..shuffleCount) {
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val random = com.example.firstapp.utils.RandomUtils.Companion.getRandom(length - i)
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out[i - 1] = intArray[random]
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val temp = intArray[length - i]
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intArray[length - i] = intArray[random]
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intArray[random] = temp
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}
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return out
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}
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}
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/**
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* Don't let anyone instantiate this class.
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*/
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init {
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throw Error("Do not need instantiate!")
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}
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}
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