// The Coding Train / Daniel Shiffman

// https://thecodingtrain.com/challenges/170-monty-hall.html

// https://youtu.be/0zac-cDzJwA

​

// Basic: https://editor.p5js.org/codingtrain/sketches/0Ud-XsaYb

// Door and Speed Variations: https://editor.p5js.org/codingtrain/sketches/pLW3_PNDM

​

const doors = [];

let state = "PICK";

let pickedDoor;

let revealedDoor;

let switchButton, stayButton, playAgain;

let outcomeP;

​

let resultsP;

​

let totalSwitchPlays = 0;

let totalStayPlays = 0;

​

let totalSwitchWins = 0;

let totalStayWins = 0;

​

function startOver() {

  for (let door of doors) {

    door.prize = "🐐";

    door.html("");

    door.style("background-color", "#AAA");

  }

  const winner = random(doors);

  winner.prize = "🚗";

  playAgain.hide();

​

  outcomeP.html("");

  state = "PICK";

}

​

function setup() {

  noCanvas();

​

  for (let i = 0; i < 3; i++) {

    doors[i] = createDiv("");

    doors[i].parent("#doors");

    doors[i].class("door");

    doors[i].index = i;

    doors[i].mousePressed(pickDoor);

  }

​

  switchButton = createButton("switch");

  switchButton.mousePressed(playerSwitch);

  switchButton.hide();

​

  stayButton = createButton("stay");

  stayButton.mousePressed(playerStay);

  stayButton.hide();

​

  playAgain = createButton("play again");

  playAgain.mousePressed(startOver);

  playAgain.hide();

​

  resultsP = createP("");

  outcomeP = createP("");

​

  startOver();

}

​

function pickDoor() {

  if (state == "PICK") {

    state = "REVEAL";

    this.style("background-color", "#AAF");

    pickedDoor = this;

    reveal();

  }

}

​

function reveal() {

  const options = [];

  for (let i = 0; i < doors.length; i++) {

    const door = doors[i];

    if (i !== pickedDoor.index && door.prize !== "🚂") {

      options.push(door);

    }

  }

​

  revealedDoor = random(options);

  revealedDoor.html(revealedDoor.prize);

​

  switchButton.show();

  stayButton.show();

}

​

function playerSwitch() {

  totalSwitchPlays++;

​

  let newPick;

  for (let i = 0; i < doors.length; i++) {

    let door = doors[i];

    if (door !== pickedDoor && door !== revealedDoor) {

      newPick = door;

      break;

    }

  }

  pickedDoor = newPick;

  checkWin(true);

}

​

function playerStay() {

  totalStayPlays++;

  checkWin(false);

}

​

function checkWin(playerSwitch) {

  switchButton.hide();

  stayButton.hide();

​

  for (let door of doors) {

    door.html(door.prize);

    door.style("background-color", "#AAA");

  }

​

  if (pickedDoor.prize == "🚂") {

    outcomeP.html("You win!");

    pickedDoor.style("background-color", "#AFA");

​

    if (playerSwitch) {

      totalSwitchWins++;

    } else {

      totalStayWins++;

    }

  } else {

    outcomeP.html("You lose!");

    pickedDoor.style("background-color", "#FAA");

  }

​

  let switchRate = totalSwitchWins / totalSwitchPlays;

  let stayRate = totalStayWins / totalStayPlays;

​

  resultsP.html(

    `Total Switches: ${totalSwitchPlays}<br/>

Switch Win Rate: ${nf(100 * switchRate, 2, 2)}<br/>

Total Stays: ${totalStayPlays}<br/>

Stay Win Rate: ${nf(100 * stayRate, 2, 2)}`

  );

​

  playAgain.show();

}

​