How much did you spend on subway in a month in BeiJing

monthlyCost

function monthlyCost(price){

	var sum = 0;
	var n = 23;
	var d08,d05;
	d08 = price * 0.8;
	d05 = price * 0.5;
	for(var i=0;i<n*2;i++){
		sum += price;
		if(sum>=100 && price > d08){
			price = d08;
			console.info((i/2)+" day 80%");
		}else if(sum >= 150  && price > d05){
			price = d05;
			console.info((i/2)+" day 50%");
		}
	}
	console.info("one month cost " + sum);
}

try monthlyCost(6), about 207.

Now it's monthlyCost(7), about 232. :(