gistfile1.txt

var initial_money = 40;
var num_play_times = 30;
var default_bet = 3;

var total_simulations = 1000;
var survives = 0;
var final_money = [];

var flip = function() {
	return Math.random() < (18/38);
};

for (var i=0;i<total_simulations;i++){
	var survived = true;
	var money = initial_money;
	
	var bet = default_bet;

	for(var j = 0; j < num_play_times; j++) {
		var winning_flip = flip();
		
		if (winning_flip) {
			money += bet;
			bet = default_bet;
		} else {
			money -= bet;
			bet *= 2;
		}

		if(money < 0){
			survived = false;
			break;
		}
	}

	if (survived && money > initial_money) {
		survives += 1;
		final_money.push(money);
	}
};

var average_money_earned = (final_money.reduce(function(s, e){
	s += e;
	return s;
}, 0) / (final_money.length));

console.log("survived", survives * 100 / total_simulations, "% of the time");
console.log("average money if you survived is $", average_money_earned);