[백준 - 11758] CCW

문제링크

• CCW 알고리즘

data class Position(val x: Int, val y: Int, val z: Int)

fun main() {
    val bufferedReader = System.`in`.bufferedReader()
    val bufferedWriter = System.out.bufferedWriter()

    val positions = mutableListOf<Position>()
    repeat(3) {
        val (x, y) = bufferedReader
            .readLine()
            .split(" ")
            .map { it.toInt() }
        positions.add(Position(x, y, 0))
    }
    val abVector = getVector(positions[0], positions[1])
    val acVector = getVector(positions[0], positions[2])
    val crossProduct = getCrossProduct(abVector, acVector)
    when {
        crossProduct.z == 0 -> bufferedWriter.write("0")
        crossProduct.z > 0 -> bufferedWriter.write("1")
        else -> bufferedWriter.write("-1")
    }

    bufferedReader.close()
    bufferedWriter.close()
}

fun getVector(position1: Position, position2: Position): Position {
    return Position(position2.x - position1.x, position2.y - position1.y, 0)
}

fun getCrossProduct(vector1: Position, vector2: Position): Position {
    return Position(
        (vector1.y * vector2.z) - (vector1.z * vector2.y),
        (vector1.z * vector2.x) - (vector1.x * vector2.z),
        (vector1.x * vector2.y) - (vector1.y * vector2.x)
    )
}

주석 없는 코드를 만들기 위해 노력하는 개발자입니다.

혹시라도 의도가 분명하지 않아보이는 (이해가 되지 않는) 코드가 있으시다면 편하게 답변 달아주시면 정말 감사하겠습니다.