A demonstration of the Monty Hall problem.

monty_hall.js

function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min)) + min;
}

var monty = function(doSwitch) {
  var tryCount = 10000;
  var winCount = 0.0;

  for (var i = 0; i < tryCount; i++) {
    var car = getRandomInt(0, 3);

    var choice = getRandomInt(0, 3);
    console.log("Your choice: " + choice);

    var openDoor = 0;
    while (openDoor === choice || openDoor === car) {
      openDoor += 1;
    }

    console.log("Open door: " + openDoor);

    if (doSwitch) {
      choice = 1 ^ 2 ^ choice ^ openDoor;
    }

    console.log("Car door: " + car);

    console.log("Correct? " + (car == choice));

    if (car === choice) {
      winCount += 1;
    }
    
  }

  return winCount / tryCount;
}

console.log("Win ratio: " + monty(true));