//Swift 4.0

var mapView: BMKMapView!

func showAllLocations(locations: [CLLocationCoordinate2D]) {
    guard locations.count >= 1 else { return }
    var minLat = locations[0].latitude
    var maxLat = locations[0].latitude
    var minLon = locations[0].longitude
    var maxLon = locations[0].longitude

    for location in locations {
      minLat = min(minLat, location.latitude)
      maxLat = max(maxLat, location.latitude)
      minLon = min(minLon, location.longitude)
      maxLon = max(maxLon, location.longitude)
    }

    let padding = (maxLat - minLat) * 0.01 //padding according to (maxLat - minLat) value
    let center = CLLocationCoordinate2D(latitude: (minLat + maxLat) / 2, longitude: (minLon + maxLon) / 2)
    let span = BMKCoordinateSpan(latitudeDelta: maxLat - minLat + padding, longitudeDelta: maxLon - minLon + padding)
    let region = BMKCoordinateRegion(center: center, span: span)
    mapView.setRegion(region, animated: true)
  }