private void addToIslands(Map<Coordinate, Island> coordinateMapper, Coordinate c) {
int diff = -1;
VariantGraph.Vertex neighbor = null;
try {
neighbor = vertexAt(c.row + diff, c.column + diff);
} catch (IndexOutOfBoundsException e) {
// ignored
}
if (neighbor != null) {
Coordinate neighborCoordinate =
new Coordinate(c.row + diff, c.column + diff, new Match(neighbor, null));
Island island = coordinateMapper.get(neighborCoordinate);
if (island == null) {
// LOG.debug("new island");
Island island0 = new Island();
island0.add(neighborCoordinate);
island0.add(c);
coordinateMapper.put(neighborCoordinate, island0);
coordinateMapper.put(c, island0);
} else {
// LOG.debug("add to existing island");
island.add(c);
coordinateMapper.put(c, island);
}
}
}
// Since the coordinates in allMatches are ordered from upper left to lower right,
// we don't need to check the lower right neighbor.
@Override
public Set<Island> getIslands() {
Map<Coordinate, Island> coordinateMapper = new HashMap<>();
List<Coordinate> allMatches = allMatches();
for (Coordinate c : allMatches) {
// LOG.debug("coordinate {}", c);
addToIslands(coordinateMapper, c);
}
Set<Coordinate> smallestIslandsCoordinates = new HashSet<>(allMatches);
smallestIslandsCoordinates.removeAll(coordinateMapper.keySet());
for (Coordinate coordinate : smallestIslandsCoordinates) {
Island island = new Island();
island.add(coordinate);
coordinateMapper.put(coordinate, island);
}
return new HashSet<>(coordinateMapper.values());
}