public int compareTo(FloorCell fc) {

		if (fc.alreadyCleaned() && !this.alreadyCleaned()) {
			return -1;
		} else if (!fc.alreadyCleaned() && this.alreadyCleaned()) {
			return 1;
		}

		else { if (fc.getVisited() > this.getVisited()) {
				return -1;
			} else if (fc.getVisited() < this.getVisited()) {
				return 1;
			} else {
				if (fc.getVisitedTime() > this.getVisitedTime()) {
					return -1;
				} else if (fc.getVisitedTime() < this.getVisitedTime()) {
					return -1;
				} else {
                    return 0;
                }
			}

		}
	}