public Dijkstra(MapLocation... sources) {
this.sources = new LocSet(sources);
for (MapLocation source : sources) {
queue.insert(0, source);
distance[source.x][source.y] = 0;
// parent[source.x][source.y] = source;
// leave as null to cause exceptions if we accidentally try to use it
// from[source.x][source.y] = Direction.NONE;
}
}
/**
* Compute until either bytecodes have run out or we find a destination.
*
* @param end Hash-map of destination.
* @param bytecodes The bytecode limit.
* @param broadcast Whether to broadcast the results (used by the HQ).
* @return Whether we found a destination.
*/
public boolean compute(boolean[][] end, int bytecodes, boolean broadcast) {
// cache variables
int min, w, x, y;
int[] weight;
MapLocation next, nbr, prev, p;
Direction dir;
final BucketQueue<MapLocation> queue = this.queue;
final int[][] distance = this.distance;
final Direction[][] from = this.from;
// final MapLocation[][] parent = this.parent;
final boolean[][] unsafe = getUnsafe();
// int iters = 0;
// int bc = Clock.getBytecodeNum();
while (queue.size > 0) {
// iters++;
if (Clock.getBytecodeNum() >= bytecodes - 500) {
break;
}
// RC.setIndicatorString(0, Integer.toString(min));
// ALERT: queue.min is valid only after a call to deleteMin()!
next = queue.deleteMin();
min = queue.min;
x = next.x;
y = next.y;
// check if we have already visited this node
if (min == distance[x][y]) {
if (unsafe[x][y]) min += 100;
dir = from[x][y];
/*
* if (dir != null) {
* prev = next.subtract(dir);
* p = parent[prev.x][prev.y];
* if (min <= distance[p.x][p.y] + PARENT_DIST) {
* parent[x][y] = p;
* } else {
* parent[x][y] = prev;
* }
* }
*/
if (broadcast) {
try {
messagingSystem.writePathingInfo(next, dir, min, null /* parent[x][y] */);
} catch (GameActionException e) {
// e.printStackTrace();
}
}
// if (end[x][y]) {
// reached = next;
// break;
// }
weight = WEIGHT[RC.senseTerrainTile(next).ordinal()];
int i;
if (dir == null) {
dir = Direction.NORTH;
i = 8;
} else if (dir.isDiagonal()) {
dir = dir.rotateLeft().rotateLeft();
i = 5;
} else {
dir = dir.rotateLeft();
i = 3;
}
for (; --i >= 0; dir = dir.rotateRight()) {
nbr = next.add(dir);
if (RC.senseTerrainTile(nbr).isTraversableAtHeight(RobotLevel.ON_GROUND)) {
w = min + weight[dir.ordinal()];
x = nbr.x;
y = nbr.y;
if (from[x][y] == null) {
queue.insert_fast(w, nbr);
// System.out.println("inserted " + nbr + " with distance " + w + " from " + dir);
distance[x][y] = w;
from[x][y] = dir;
} else {
if (w < distance[x][y]) {
queue.insert_fast(w, nbr);
distance[x][y] = w;
from[x][y] = dir;
}
}
}
}
}
}
// bc = Clock.getBytecodeNum() - bc;
// RC.setIndicatorString(2, "average Dijkstra bytecodes: " + bc / iters);
return reached != null;
}