// Create a map
const map = new google.maps.Map(document.getElementById('map'), {
  zoom: 10,
  center: { lat: 37.5, lng: 127 },
});

// Create an array of markers
const markers = [
  { lat: 37.530, lng: 127.055 },
  { lat: 37.550, lng: 127.035 },
  { lat: 37.570, lng: 127.015 },
  // Adding more markers...
];

// Create a marker clusterer
const markerCluster = new MarkerClusterer(map, markers, {
  imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m',
});

// Update marker positions in real-time
function updateMarkerPositions() {
  // Get updated marker positions from the server
  // ...

  // Clear all existing markers
  markerCluster.clearMarkers();

  // Create new markers with updated positions
  const updatedMarkers = [
    { lat: 37.530, lng: 127.060 },
    { lat: 37.550, lng: 127.040 },
    { lat: 37.570, lng: 127.020 },
    // Adding more updated markers...
  ];

  // Add updated markers to the clusterer
  markerCluster.addMarkers(updatedMarkers);
}

// Call the updateMarkerPositions function periodically
setInterval(updateMarkerPositions, 5000);