private int initMaps(BipartiteGraph<L, R> graph) {
List<L> verticesL = graph.getLeftVertices();
rToLMap = new HashMap<String, Set<String>>(graph.getRightVertices().size());
qVerticesMap = new HashMap<String, CoverVertex<L, R>>(verticesL.size());
int maxAdjCount = 0;
for (L vertex : verticesL) {
CoverVertex<L, R> qv = new CoverVertex<L, R>(vertex, graph);
qVerticesMap.put(vertex.getLabel(), qv);
Set<String> adjRLabels = qv.getAdjRLabels();
for (String rLabel : adjRLabels) {
Set<String> adjLLabels = rToLMap.get(rLabel);
if (adjLLabels == null) {
adjLLabels = new HashSet<String>();
rToLMap.put(rLabel, adjLLabels);
}
adjLLabels.add(vertex.getLabel());
}
maxAdjCount = Math.max(maxAdjCount, adjRLabels.size());
}
return maxAdjCount;
}
private void addRemainingSetCoverVertices(List<L> setCover) {
for (int i = adjCounts.length - 1; i >= 0; i--) {
List<String> qvWithAdjCount = adjCounts[i];
// if there are no vertices with this adjacency count go to the next iteration
if (qvWithAdjCount == null || qvWithAdjCount.size() == 0) continue;
// This is where we resolve ties.
// getBestVertex will also sort so that the best vertex is at index 0.
String lLabel = getBestVertex(qvWithAdjCount);
// String lLabel = qvWithAdjCount.get(0);
qvWithAdjCount.remove(0);
// add this to the set cover
CoverVertex<L, R> qv = qVerticesMap.get(lLabel);
setCover.add(qv.getVertex());
// get all the labels of all vertices adjacent to this vertex
// and remove them from the graph.
for (String rLabel : qv.getAdjRLabels()) {
Set<String> lLabels = rToLMap.get(rLabel);
// other L vertices adjacent to this R vertex
for (String label : lLabels) {
CoverVertex<L, R> qvl = qVerticesMap.get(label);
if (qvl == qv) continue;
removeAdjacentVertx(qvl, rLabel);
}
}
if (qvWithAdjCount.size() > 0) i++;
}
}
private void initUniqAdjacencyCounts() {
for (CoverVertex<L, R> qv : qVerticesMap.values()) {
Set<String> adjR = qv.getAdjRLabels();
int uniqCount = 0;
for (String r : adjR) {
if (rToLMap.get(r).size() == 1) {
uniqCount++;
}
}
qv.setUniqAdjacentcount(uniqCount);
}
}
private void addVerticesWithUniqAdjacent(List<L> setCover) {
Iterator<CoverVertex<L, R>> iter = qVerticesMap.values().iterator();
while (iter.hasNext()) {
CoverVertex<L, R> qv = iter.next();
if (qv.getUniqAdjacentcount() > 0) {
setCover.add(qv.getVertex());
}
}
// remove the vertices already added (and their adjacent vertices) from the graph
for (L v : setCover) {
CoverVertex<L, R> qv = qVerticesMap.get(v.getLabel());
// get all the labels of all vertices adjacent to this vertex
// and remove them from the graph.
for (String rLabel : qv.getAdjRLabels()) {
Set<String> lLabels = rToLMap.get(rLabel);
// other L vertices adjacent to this R vertex
for (String label : lLabels) {
CoverVertex<L, R> qvl = qVerticesMap.get(label);
if (qvl == qv) continue;
removeAdjacentVertx(qvl, rLabel);
}
}
}
// remove these vertices from the adjacency count list
// This should be done AFTER the previous step (removing all R vertices for vertices in set
// cover
// and updating L vertices that matched to them).
for (L v : setCover) {
CoverVertex<L, R> qv = qVerticesMap.get(v.getLabel());
List<String> qvWithAdjCount = adjCounts[qv.getAdjacentCount()];
Iterator<String> iterL = qvWithAdjCount.iterator();
boolean removed = false;
while (iterL.hasNext()) {
String label = iterL.next();
if (label.equals(qv.getVertex().getLabel())) {
iterL.remove();
removed = true;
break;
}
}
if (!removed)
throw new IllegalArgumentException("Vertex not removed; " + qv.getVertex().getLabel());
}
}
