검색,탐색 - moggaa/kotlin-coding-test GitHub Wiki

fun binarySearch(){
    //정렬이 되어있어야 사용 가능 (검색 실패시 -> 인덱스 음수 반환)
    val arr = IntArray(100){
        it + 1
    }
    val index = arr.binarySearch(22)
}

fun dfs(index: Int) {
    visited[index] = true
    println(index)

    if(condition){

    }
    
    // 구현
    for (next in edges[index]) {
        if (!visited[next]) {
            dfs(next)
        }
    }
}

fun bfs(start: Int) {
        queue.add(start)
        visited[start] = true

        while (queue.isNotEmpty()) {
            val head = queue.poll() // 첫 원소 반환 후 remove

						println(head)
						if(condition){
						
						}
						
            for (next in edges[head]) {
                if (!visited[next]) {
                    visited[next] = true
                    queue.add(next)
                }
            }
        }
    }

fun <T> permutation(el: List<T>, fin: List<T> = listOf(), sub: List<T> = el ): List<List<T>> {
    return if(sub.isEmpty()) listOf(fin)
        else sub.flatMap { permutation(el, fin + it, sub - it) }
}

fun <T> combination(answer: MutableList<List<T>>, el: List<T>, ck: Array<Boolean>, start: Int, target: Int) {
    if(target == 0) {
        answer.addAll( listOf(el.filterIndexed { index, t -> ck[index] }) )
    } else {
        for(i in start until el.size) {
            ck[i] = true
            combination(answer, el, ck, i + 1, target - 1)
            ck[i] = false
        }
    }
}

fun main(args: Array<String>) {
    var arr = listOf(1, 2, 3, 4)    // 1. Int
    //var arr = "asdf".toList()   // 2. String

    for(i in 1 .. arr.size) {
        val answer = mutableListOf<List<Int>>()     // 1. Int
        // val answer = mutableListOf<List<Char>>() // 2. String
        println("================$i 개====================")
        combination(answer, arr, Array<Boolean>(arr.size) { false }, 0,  i)
        answer.forEach { println(it) }
    }

}