Method getRank

java/Chapter 11/Question11_8/RankNode.java:29–46

(int d)

	}
	
	public int getRank(int d) {
		if (d == data) {
			return left_size;
		} else if (d < data) {
			if (left == null) {
				return -1;
			} else {
				return left.getRank(d);
			}
		} else {
			int right_rank = right == null ? -1 : right.getRank(d);
			if (right_rank == -1) {
				return -1;
			} else {
				return left_size + 1 + right_rank;
			}
		}
	}
}