game.fs

type Bridge = { RunwayLength: int; GapSize: int; LandingSize: int }
type Bike = { Speed: int; Position: int }

type BikeSate =
    | OnTheRunway
    | JustBeforeGap
    | InFlight
    | AfterGap

type BikeSpeed =
    | TooSlow
    | TooFast
    | TargetSpeed

let bridge = { RunwayLength = 1; GapSize = 1; LandingSize = 1 } 

// Get current position
let bikeState bike =
    if bike.Position >= bridge.RunwayLength + bridge.GapSize then AfterGap
    elif bike.Position > (bridge.RunwayLength - bike.Speed) then JustBeforeGap
    elif bike.Position < bridge.RunwayLength then OnTheRunway
    else InFlight
 
// Get current speed
let bikeSpeed speed =
    let targetSpeed = bridge.GapSize + 1
    if speed < targetSpeed then TooSlow
    elif speed > targetSpeed then TooFast
    else TargetSpeed

let getAction state =
    match bikeState state, bikeSpeed state.Speed with
    | OnTheRunway, TooSlow -> "SPEED"
    | OnTheRunway, TooFast -> "SLOW"
    | OnTheRunway, TargetSpeed | InFlight, _ -> "WAIT"
    | JustBeforeGap, _ -> "JUMP"
    | AfterGap, _ -> "SLOW"