Given a list of unsorted integers, find maximum binary string or maximum integer whichever comes highest

max_binary.js

fn = (l, lo, hi, b) => {
	if (lo<hi) {
		mid = parseInt((lo+hi)/2);
		fn(l, lo, mid, b);
		fn(l, mid+1, hi, b);
		}
	else {
		let c = l[lo].toString(2).match(/1+/gi).join('').length;
                console.log(c, l[lo]);
		if (b[0] < l[lo]) b[0] = l[lo];
	}
};

b = [0];

fn(l, 0, l.length-1, b);