fun Collection.powerset(): Set = powerset(this, setOf(setOf())) private tailrec fun powerset(left: Collection, acc: Set): Set = when { left.isEmpty() -> acc else ->powerset(left.drop(1), acc + acc.map { it + left.first() }) } fun main() { val list1 = listOf(1,2,3,4,5,6,7,8) val list2 = listOf(1,2,3) val a = list1.powerset() println(a) println(a.size) val b = list2.powerset() println(b) } github...
ํ์ฅํจ์ info๋ฅผ ํตํด ํธ์ถ ํด๋์ค๋ช ๊ณผ ๋ฉ์๋๋ช ์ถ๋ ฅ class PopcornPopper{ fun on() { info() } } fun T.info(): T { val res = this Throwable().stackTrace[1].apply { println("${generateTag()} ${generateMessage(res)}") } return this } fun T.info(msg: () -> Any): T { Throwable().stackTrace[1].apply { println("${generateTag()} ${generateMessage(msg())}") } return this } fun StackTraceElement.generateTag() = className.subst..
์ ์ ํ ํด๋์ค์ ์ธํฐํ์ด์ค๋ฅผ ํฌ๋ผ์ด์ธํธ์์ ์ฌ์ฉํ๊ณ ์ ํ๋ ๋ค๋ฅธ ์ธํฐํ์ด์ค๋ก ๋ณํ. ์ธํฐํ์ด์ค ํธํ์ฑ ๋ฌธ์ ๋ก ๊ฐ์ด ์ธ ์ ์๋ ํด๋์ค๋ค์ ์ฐ๊ฒฐํ์ฌ ์ฌ์ฉ ๊ฐ๋ฅ ๊ฐ๋จ ์์ ์ฝ๋ import kotlin.test.* import kotlin.time.* interface Duck { fun quack() fun fly() } class MallardDuck : Duck { override fun quack() { println("Quack") } override fun fly() { println("I'm flying") } } interface Turkey { fun gobble() fun fly() } class WildTurkey : Turkey { override fun gobble() { printl..
๊ธฐ๋ณธํ class Trie { data class TrieNode(var isEndOfWord : Boolean, val children : MutableMap) val root = TrieNode(false, mutableMapOf()) fun insert(word : String) { var currentNode = root word.forEach{ char -> val child = currentNode.children[char] ?: TrieNode(false, mutableMapOf()) currentNode.children[char] = child currentNode = child } currentNode.isEndOfWord = true } fun search(word : String) :..