Robot Bound In Circle via Leetcode. Beats 100% memory 🎉 and beats 6.67% on runtime 😭

RobotBoundedInCircle.kt

class Solution {
    fun isRobotBounded(instructions: String): Boolean {
        val robot = Robot()
        repeat(4) {
            instructions.forEach { instruction -> 
                when (instruction) {
                    'G' -> robot.move()
                    'R' -> robot.turnRight()
                    'L' -> robot.turnLeft()
                }
            }
        }
        return robot.coordinates.horizontal == 0 && robot.coordinates.vertical == 0
    }
}

class Robot {

    private var orientation: Orientation = Orientation.N

    var coordinates = Pair<Int, Int>(0, 0)
        private set

    fun move() {
        when (orientation) {
            Orientation.N -> coordinates = Pair(coordinates.horizontal, coordinates.vertical + 1)
            Orientation.S -> coordinates = Pair(coordinates.horizontal, coordinates.vertical - 1)
            Orientation.E -> coordinates = Pair(coordinates.horizontal + 1, coordinates.vertical)
            Orientation.W -> coordinates = Pair(coordinates.horizontal - 1, coordinates.vertical)
        }
    }

    fun turnRight() {
        orientation = orientation.turnRight()
    }

    fun turnLeft() {
        orientation = orientation.turnLeft()
    }
}
    
sealed class Orientation(val degrees: Int) {
    object N : Orientation(0)
    object S : Orientation(180)
    object E : Orientation(90)
    object W : Orientation(270)

    fun turnRight(): Orientation {
        return Orientation.create(degrees + 90)
    }

    fun turnLeft(): Orientation {
        return Orientation.create(degrees - 90)
    }


    companion object {
        fun create(degrees: Int): Orientation {
            return when (degrees) {
                0, in 360..Int.MAX_VALUE -> Orientation.N
                90 -> Orientation.E
                180 -> Orientation.S
                else -> Orientation.W
            }
        }   
    }
}

val Pair<Int, Int>.horizontal: Int
    get() = first

val Pair<Int, Int>.vertical: Int
    get() = second