montey_hall.ts

function shuffle<T>(o: T[]): T[] {
    for(var j, x, i = o.length; i; j = Math.floor(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
    return o;
}

enum Door {
  Zonk,
  Prize
}

class Game {

  private doors: Door[];
  private selectedDoor: number;
  private openedDoor: number;

  constructor() {
    this.doors = shuffle([
        Door.Zonk,
        Door.Zonk,
        Door.Prize
    ]);
  }

  choose(door: number): void {
    this.selectedDoor = door;
    for (let i = 0; i < 3; i++) {
      if (i !== door && this.doors[i] == Door.Zonk) {
        this.openedDoor = i;
        break;
      }
    }
  }

  switch(): void {
    for (let i = 0; i < 3; i++) {
      if (i !== this.selectedDoor && i !== this.openedDoor) {
        this.selectedDoor = i;
        break;
      }
    }
  }

  won(): boolean {
    return this.doors[this.selectedDoor] === Door.Prize;
  }

}

let wins = 0;
let losses = 0;

for (let i = 0; i < 10000; i++) {

  let game = new Game();

  let randDoor = Math.floor(Math.random() * 3);
  
  game.choose(randDoor);
  game.switch();

  if (game.won()) {
    wins++;
  } else {
    losses++;
  }

}

console.log("wins:", wins, "losses:", losses);