Monty Hall Simulation

monty-hall-simulation

function montyhallSimulation(playerChangeOpt, testcases)
{
	playerChangeOpt = typeof playerChangeOpt !== 'undefined' ? playerChangeOpt : true;
	testcases = typeof testcases !== 'undefined' ? testcases : 100;
	
	var right = 0, wrong = 0;
	for(i=0 ; i<testcases ; i++) {
		var carPos = Math.floor(Math.random()*3);
		var playerOpt = Math.floor(Math.random()*3);
		
		var firstGoat;
		while(firstGoat == undefined || firstGoat == carPos || firstGoat == playerOpt)
			firstGoat = Math.floor(Math.random()*3);
		
		if(playerChangeOpt) {
			var newOpt;
			while(newOpt == undefined || newOpt == firstGoat || newOpt == playerOpt)
				newOpt = Math.floor(Math.random()*3);
			playerOpt = newOpt;
		}
		
		carPos == playerOpt ? right++ : wrong++;
	}
	
	console.log("Winning: " + right*100/testcases + "%");
	console.log("Loses: " + wrong*100/testcases + "%");
}

monty-hall-simulation test

// Player change his choice, 100 testcases
montyhallSimulation();

// Player change his choice, 1k testcases
montyhallSimulation(true, 1000);

// Player do not change his choice, 1k testcases
montyhallSimulation(false, 1000);