Measurement closest(double beta, Node t[]) {	Measurement self = get_distance_tcp(t, -1);	double avg_lat = array_avg(self.distance);	double min_lat = array_min(self.distance);	double max_lat = array_max(self.distance);	Node ring_m[] = array_intersect(		ring_ge((1.0 - beta) * min_lat), ring_le((1.0 + beta) * max_lat));	if (array_size(ring_m) == 0) {		return self;	}	Measurement r_lat[] = get_distance_tcp(ring_m, t, 		ceil((2.0 * beta + 1.0) * max_lat));	int min_index = -1; 	min_lat = avg_lat;	for (int i = 0; i < array_size(r_lat); i = i + 1) { 		double cur_lat = array_avg(r_lat[i].distance);		if (cur_lat < min_lat) {			min_index = i;			min_lat = cur_lat; 		}	}	if (min_index == -1) {		return self;	}	Measurement min_n = r_lat[min_index];		if (min_n.addr != 0 && min_lat < (avg_lat * beta)) {		Measurement ret_n = rpc(ring_m[min_index], closest, beta, t);		if (ret_n.addr != 0) {			return ret_n;		}	}		return min_n;}int main() {	Node t1 = {dns_lookup("www.cs.berkeley.edu"), 80, 0, 0};	Node ts[] = {t1};	Node e = {dns_lookup("planetlab1.cs.cornell.edu"), 3964, 0, 0};		Measurement r = rpc(e, closest, 0.5, ts);	if (r.addr == 0) {		r.addr = e.addr;		r.port = e.port;	}	print("Closest node is ");	println(dns_addr(r.addr));	for (int i = 0; i < array_size(r.distance); i = i + 1) {		print("--> ");		print(r.distance[i]);		print(" from ");		println(dns_addr(ts[i].addr));	}	return 0;}