public int[] dijkstra(Node source) {
dist = new int[nodes.length];
previous = new Node[nodes.length];
Arrays.fill(dist, Integer.MAX_VALUE);
dist[source.id] = 0;
Queue<Node> queue = new PriorityQueue<Node>();
for (int i = 0; i < nodes.length; i++) {
queue.add(nodes[i]);
}
while (!queue.isEmpty()) {
Node u = queue.poll();
if (dist[u.id] == Integer.MAX_VALUE) break;
for (int i = 0; i < nodes.length; i++) {
if (!u.equals(nodes[i]) && weights[u.id][i] > 0) {
int distance = dist[u.id] + weights[u.id][i];
if (distance < dist[nodes[i].id]) {
dist[nodes[i].id] = distance;
previous[nodes[i].id] = u;
}
}
}
}
return dist;
}
public int countPaths(Node source, Node destination) {
if (source.equals(destination)) return 1;
int count = 0;
for (int i = 0; i < nodes.length; i++) {
if (!source.equals(nodes[i]) && weights[source.id][i] > 0) {
count = count + countPaths(nodes[i], destination);
}
}
return count;
}
public boolean pathExists(Node source, Node destination) {
if (source.equals(destination)) return true;
boolean pathExists = false;
for (int i = 0; i < nodes.length; i++) {
if (!source.equals(nodes[i]) && weights[source.id][i] > 0) {
pathExists = pathExists || pathExists(nodes[i], destination);
if (pathExists) break;
}
}
return pathExists;
}
