Program: 164375
Project: 164375
Buggy source:
protected void assignRoomType(){
  int specialRooms=0;
  for (  Room r : rooms) {
    if (r.type == Type.NULL && r.connected.size() == 1) {
      if (specials.size() > 0 && r.width() > 3 && r.height() > 3 && Random.Int(specialRooms * specialRooms + 2) == 0) {
        if (pitRoomNeeded) {
          r.type=Type.PIT;
          pitRoomNeeded=false;
          specials.remove(Type.ARMORY);
          specials.remove(Type.CRYPT);
          specials.remove(Type.LABORATORY);
          specials.remove(Type.LIBRARY);
          specials.remove(Type.STATUE);
          specials.remove(Type.TREASURY);
          specials.remove(Type.VAULT);
          specials.remove(Type.WEAK_FLOOR);
        }
 else         if (Dungeon.depth % 5 == 2 && specials.contains(Type.LABORATORY)) {
          r.type=Type.LABORATORY;
        }
 else         if (Dungeon.depth >= Dungeon.transmutation && specials.contains(Type.MAGIC_WELL)) {
          r.type=Type.MAGIC_WELL;
        }
 else {
          int n=specials.size();
          r.type=specials.get(Math.min(Random.Int(n),Random.Int(n)));
          if (r.type == Type.WEAK_FLOOR) {
            weakFloorCreated=true;
          }
        }
        Room.useType(r.type);
        specials.remove(r.type);
        specialRooms++;
      }
 else       if (Random.Int(2) == 0) {
        HashSet<Room> neigbours=new HashSet<Room>();
        for (        Room n : r.neigbours) {
          if (!r.connected.containsKey(n) && !Room.SPECIALS.contains(n.type) && n.type != Type.PIT) {
            neigbours.add(n);
          }
        }
        if (neigbours.size() > 1) {
          r.connect(Random.element(neigbours));
        }
      }
    }
  }
  int count=0;
  for (  Room r : rooms) {
    if (r.type == Type.NULL) {
      int connections=r.connected.size();
      if (connections == 0) {
      }
 else       if (Random.Int(connections * connections) == 0) {
        r.type=Type.STANDARD;
        count++;
      }
 else {
        r.type=Type.TUNNEL;
      }
    }
  }
  while (count < 4) {
    Room r=randomRoom(Type.TUNNEL,1);
    if (r != null) {
      r.type=Type.STANDARD;
      count++;
    }
  }
}

Fixed version (ground truth):
protected boolean assignRoomType(){
  int specialRooms=0;
  for (  Room r : rooms) {
    if (r.type == Type.NULL && r.connected.size() == 1) {
      if (specials.size() > 0 && r.width() > 3 && r.height() > 3 && Random.Int(specialRooms * specialRooms + 2) == 0) {
        if (pitRoomNeeded) {
          r.type=Type.PIT;
          pitRoomNeeded=false;
          specials.remove(Type.ARMORY);
          specials.remove(Type.CRYPT);
          specials.remove(Type.LABORATORY);
          specials.remove(Type.LIBRARY);
          specials.remove(Type.STATUE);
          specials.remove(Type.TREASURY);
          specials.remove(Type.VAULT);
          specials.remove(Type.WEAK_FLOOR);
        }
 else         if (Dungeon.depth % 5 == 2 && specials.contains(Type.LABORATORY)) {
          r.type=Type.LABORATORY;
        }
 else         if (Dungeon.depth >= Dungeon.transmutation && specials.contains(Type.MAGIC_WELL)) {
          r.type=Type.MAGIC_WELL;
        }
 else {
          int n=specials.size();
          r.type=specials.get(Math.min(Random.Int(n),Random.Int(n)));
          if (r.type == Type.WEAK_FLOOR) {
            weakFloorCreated=true;
          }
        }
        Room.useType(r.type);
        specials.remove(r.type);
        specialRooms++;
      }
 else       if (Random.Int(2) == 0) {
        HashSet<Room> neigbours=new HashSet<Room>();
        for (        Room n : r.neigbours) {
          if (!r.connected.containsKey(n) && !Room.SPECIALS.contains(n.type) && n.type != Type.PIT) {
            neigbours.add(n);
          }
        }
        if (neigbours.size() > 1) {
          r.connect(Random.element(neigbours));
        }
      }
    }
  }
  int count=0;
  for (  Room r : rooms) {
    if (r.type == Type.NULL) {
      int connections=r.connected.size();
      if (connections == 0) {
      }
 else       if (Random.Int(connections * connections) == 0) {
        r.type=Type.STANDARD;
        count++;
      }
 else {
        r.type=Type.TUNNEL;
      }
    }
  }
  while (count < 4) {
    Room r=randomRoom(Type.TUNNEL,1);
    if (r != null) {
      r.type=Type.STANDARD;
      count++;
    }
  }
  return true;
}