public PathResult dijkstra() {
PathResult p = new PathResult();
Map dMap = map.newInstance();
HashSet<Node> evaluated = new HashSet<Node>();
HashSet<Node> unevaluated = new HashSet<Node>();
HashMap<String, Double> dist = new HashMap<String, Double>();
HashMap<String, String> previous = new HashMap<String, String>();
for (int i = 0; i < dMap.getSize(); i++) {
Node toAdd = dMap.getNode(i);
unevaluated.add(toAdd);
dist.put(toAdd.getName(), Double.MAX_VALUE);
previous.put(toAdd.getName(), null);
}
dist.put("START", 0D);
Node curNode = dMap.getStartNode(), temp = null;
while (!unevaluated.isEmpty()) {
Iterator<Node> it = unevaluated.iterator();
curNode = it.next();
while (it.hasNext()) {
temp = it.next();
if (dist.get(temp.getName()) < dist.get(curNode.getName())) curNode = temp;
}
evaluated.add(curNode);
unevaluated.remove(curNode);
if (dist.get(curNode.getName()) == Double.MAX_VALUE || dMap.getEndNode().equals(curNode))
break;
for (int i = 0; i < curNode.getNumDepend(); i++) {
Node depend = curNode.getDepend(i);
if (evaluated.contains(depend)) continue;
double tempWeight =
dist.get(curNode.getName())
+ dMap.getPath(curNode.getName(), depend.getName()).getWeight();
if (tempWeight < dist.get(depend.getName())) {
dist.put(depend.getName(), tempWeight);
previous.put(depend.getName(), curNode.getName());
}
}
}
p.setWeight(dist.get(curNode.getName()));
String name = curNode.getName();
while (previous.get(curNode.getName()) != null) {
curNode = dMap.getFromName(previous.get(curNode.getName()));
name = curNode.getName() + "," + name;
}
p.setPath(name);
return p;
}
public void readFile(String fn) {
try {
map = new Map();
map.setStartNode(new Node("START", this));
Scanner scan = new Scanner(new File("src/mwpf/" + fn + ".txt"));
/*
* 1: # of nodes (A-Z, Aa-Zz, etc)
* 2: # of paths, p
* 3-p+2: [A] [B] [Weight]
*/
int numNodes = Integer.valueOf(scan.nextLine());
for (int i = 0; i < numNodes; i++) {
int temp = i;
String name = "";
int log = (int) Math.floor(Math.log(temp) / Math.log(26));
if (log == Integer.MIN_VALUE) log = 0;
// name = ""+((char)(65+temp/((int)Math.pow(26, log))));
for (int j = 0; j <= log; j++) {
name = ((char) (65 + temp % 26)) + name;
temp = (int) Math.floor(temp / 26D) - 1;
}
map.addNode(new Node(name, this));
}
map.setEndNode(new Node("END", this));
int numPaths = Integer.valueOf(scan.nextLine());
for (int i = 0; i < numPaths; i++) {
String line = scan.nextLine();
String[] lineSplit = line.split(" ");
if (lineSplit.length != 3) continue;
// System.out.println(lineSplit[0] + " " + lineSplit[1]);
map.addPath(
new Path(
map.getFromName(lineSplit[0]),
map.getFromName(lineSplit[1]),
Double.parseDouble(lineSplit[2])));
}
scan.close();
} catch (Exception e) {
System.out.println("Failed reading file: " + e);
}
}