/**
* The kruskal static method runs the Kruskal algorithm given an EdgeList. This in effect returns
* the minimum spanning tree of a graph (MST).
*
* @param edgeList -The collection of edges for a graph.
* @return -The Collection representing the minimum spanning tree.
*/
public static Collection<Edge> kruskal(EdgeList edgeList) {
ArrayList<Edge> mST = new ArrayList<Edge>();
UnionFind dataStruct = new UnionFind(edgeList);
PriorityQueue<Edge> edges = edgeList.getEdges();
while (!edges.isEmpty()) {
Edge minEdge = edges.poll();
boolean condition = dataStruct.sameComponent(minEdge.getU(), minEdge.getV());
if (condition == false) {
dataStruct.union(minEdge.getU(), minEdge.getV());
mST.add(minEdge);
}
}
return mST;
}
public Geometry buffer(Geometry g, double distance) {
PrecisionModel precisionModel = workingPrecisionModel;
if (precisionModel == null) precisionModel = g.getPrecisionModel();
// factory must be the same as the one used by the input
geomFact = g.getFactory();
OffsetCurveBuilder curveBuilder = new OffsetCurveBuilder(precisionModel, bufParams);
OffsetCurveSetBuilder curveSetBuilder = new OffsetCurveSetBuilder(g, distance, curveBuilder);
List bufferSegStrList = curveSetBuilder.getCurves();
// short-circuit test
if (bufferSegStrList.size() <= 0) {
return createEmptyResultGeometry();
}
// BufferDebug.runCount++;
// String filename = "run" + BufferDebug.runCount + "_curves";
// System.out.println("saving " + filename);
// BufferDebug.saveEdges(bufferEdgeList, filename);
// DEBUGGING ONLY
// WKTWriter wktWriter = new WKTWriter();
// Debug.println("Rings: " + wktWriter.write(convertSegStrings(bufferSegStrList.iterator())));
// wktWriter.setMaxCoordinatesPerLine(10);
// System.out.println(wktWriter.writeFormatted(convertSegStrings(bufferSegStrList.iterator())));
computeNodedEdges(bufferSegStrList, precisionModel);
graph = new PlanarGraph(new OverlayNodeFactory());
graph.addEdges(edgeList.getEdges());
List subgraphList = createSubgraphs(graph);
PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);
buildSubgraphs(subgraphList, polyBuilder);
List resultPolyList = polyBuilder.getPolygons();
// just in case...
if (resultPolyList.size() <= 0) {
return createEmptyResultGeometry();
}
Geometry resultGeom = geomFact.buildGeometry(resultPolyList);
return resultGeom;
}
