第3回 オフラインリアルタイムどう書く: Java解答

TripY.java

package yhpg3;

import static org.junit.Assert.assertEquals;

import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

public class TripY {

	Map<String, String> dic;

	public TripY() {
		dic = new HashMap<>();
		dic.put("BAr", "C");
		dic.put("BAl", "D");
		dic.put("ABr", "E");
		dic.put("ABl", "C");
		dic.put("ACr", "B");
		dic.put("ACl", "F");
		dic.put("CAr", "D");
		dic.put("CAl", "B");
		dic.put("ADr", "F");
		dic.put("ADl", "E");
		dic.put("DAr", "B");
		dic.put("DAl", "C");
		dic.put("BCr", "F");
		dic.put("BCl", "A");
		dic.put("CBr", "A");
		dic.put("CBl", "E");
		dic.put("BEr", "D");
		dic.put("BEl", "F");
		dic.put("EBr", "C");
		dic.put("EBl", "A");
		dic.put("DEr", "F");
		dic.put("DEl", "B");
		dic.put("EDr", "A");
		dic.put("EDl", "F");
		dic.put("CFr", "E");
		dic.put("CFl", "D");
		dic.put("FCr", "A");
		dic.put("FCl", "B");
		dic.put("DFr", "C");
		dic.put("DFl", "E");
		dic.put("FDr", "E");
		dic.put("FDl", "A");
		dic.put("EFr", "D");
		dic.put("EFl", "C");
		dic.put("FEr", "B");
		dic.put("FEl", "D");
	}

	protected String execute(String input) {
		String result = "A";
		String current = "BA";

		for (int i = 0; i < input.length(); i++) {
			char c = input.charAt(i);
			if (c == 'b') {
				result += current.charAt(0);
				current = String.valueOf(current.charAt(1))
						+ String.valueOf(current.charAt(0));
			} else if (c == 'r' || c == 'l') {
				String tmp = current + String.valueOf(c);
				String to = dic.get(tmp);
				result += to;
				current = String.valueOf(current.charAt(1)) + to;
			}
		}
		return result;
	}

	public static void main(String[] args) {
		TripY trip = new TripY();
		System.out.println(trip.execute("llllllrllrlbrrr")); // ADEBADEFCBADABED
	}

	@Test
	public void testExecute() throws Exception {
		TripY trip = new TripY();

		String[][] answers = {
		/* 0 */{ "b", "AB" },
		/* 1 */{ "l", "AD" },
		/* 2 */{ "r", "AC" },
		/* 3 */{ "bbb", "ABAB" },
		/* 4 */{ "rrr", "ACBA" },
		/* 5 */{ "blll", "ABCAB" },
		/* 6 */{ "llll", "ADEBA" },
		/* 7 */{ "rbrl", "ACADE" },
		/* 8 */{ "brrrr", "ABEDAB" },
		/* 9 */{ "llrrr", "ADEFDE" },
		/* 10 */{ "lrlll", "ADFEDF" },
		/* 11 */{ "lrrrr", "ADFCAD" },
		/* 12 */{ "rllll", "ACFDAC" },
		/* 13 */{ "blrrrr", "ABCFEBC" },
		/* 14 */{ "brllll", "ABEFCBE" },
		/* 15 */{ "bbrllrrr", "ABACFDEFD" },
		/* 16 */{ "rrrrblll", "ACBACABCA" },
		/* 17 */{ "llrlrrbrb", "ADEFCADABA" },
		/* 18 */{ "rrrbrllrr", "ACBABEFCAD" },
		/* 19 */{ "llrllblrll", "ADEFCBCADEB" },
		/* 20 */{ "lrrlllrbrl", "ADFCBEFDFCB" },
		/* 21 */{ "lllrbrrlbrl", "ADEBCBACFCAB" },
		/* 22 */{ "rrrrrrlrbrl", "ACBACBADFDEB" },
		/* 23 */{ "lbrbbrbrbbrr", "ADABABEBCBCFE" },
		/* 24 */{ "rrrrlbrblllr", "ACBACFCACFDAB" },
		/* 25 */{ "lbbrblrlrlbll", "ADADFDABCFDFED" },
		/* 26 */{ "rrbbrlrlrblrl", "ACBCBADFEBEFDA" },
		/* 27 */{ "blrllblbrrrrll", "ABCFDADEDABEDFE" },
		/* 28 */{ "blrllrlbllrrbr", "ABCFDABCBEFDEDA" },
		/* 29 */{ "lbrbbrllllrblrr", "ADABABEFCBEDEBCF" },
		/* 30 */{ "rrrrbllrlrbrbrr", "ACBACABCFDEDADFC" }, };

		for (int i = 0; i < 30; i++) {
			assertEquals(answers[i][1], trip.execute(answers[i][0]));
		}
	}
}