第12回オフラインリアルタイムどう書く（Java解答）

Rotdice.java

import java.util.ArrayList;
import java.util.List;

enum Direction {
	E {
		@Override
		Dice go(Dice d) {
			return d.goEast();
		}
	},
	W {
		@Override
		Dice go(Dice d) {
			return d.goWest();
		}
	},
	S {
		@Override
		Dice go(Dice d) {
			return d.goSouth();
		}
	},
	N {
		@Override
		Dice go(Dice d) {
			return d.goNorth();
		}
	};

	abstract Dice go(Dice d);
}

class Dice {

	int top;
	int west;
	int south;

	public Dice(int t, int w, int s) {
		top = t;
		west = w;
		south = s;
	}

	public Dice goEast() {
		return new Dice(west, 7 - top, south);
	}

	public Dice goWest() {
		return new Dice(7 - west, top, south);
	}

	public Dice goSouth() {
		return new Dice(7 - south, west, top);
	}

	public Dice goNorth() {
		return new Dice(south, west, 7 - top);
	}

	@Override
	public String toString() {
		return String.valueOf(top);
	}
}

public class Rotdice {

	public String solve(String input) {
		List<Direction> directions = parse(input);

		Dice dice = new Dice(1, 3, 5);
		StringBuilder sb = new StringBuilder(dice.toString());
		for (Direction each : directions) {
			dice = each.go(dice);
			sb.append(dice.toString());
		}
		return new String(sb);
	}

	List<Direction> parse(String input) {
		List<Direction> result = new ArrayList<>();
		for (char each : input.toCharArray()) {
			result.add(Direction.valueOf(String.valueOf(each)));
		}
		return result;
	}
}

RotdiceTest.java

import static org.junit.Assert.assertEquals;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

public class RotdiceTest {
  Rotdice target;

	@Test
	public void testParse() throws Exception {
		target = new Rotdice();
		List<Direction> expected = new ArrayList<>();
		expected.add(Direction.E);
		expected.add(Direction.W);
		expected.add(Direction.S);
		expected.add(Direction.N);
		assertEquals(expected, target.parse("EWSN"));
	}

	void test(String input, String expected) {
		target = new Rotdice();
		if (expected.equals(target.solve(input))) {
			System.out.println(input + "== OK");
		} else {
			System.out.println(input + "== NG");
		}
	}

	@Test
	public void testSolve() throws Exception {
		/* 0 */test("NNESWWS", "15635624");
		/* 1 */test("EEEE", "13641");
		/* 2 */test("WWWW", "14631");
		/* 3 */test("SSSS", "12651");
		/* 4 */test("NNNN", "15621");
		/* 5 */test("EENN", "13651");
		/* 6 */test("WWNN", "14651");
		/* 7 */test("SSNN", "12621");
		/* 8 */test("NENNN", "153641");
		/* 9 */test("NWNNN", "154631");
		/* 10 */test("SWWWSNEEEN", "12453635421");
		/* 11 */test("SENWSWSNSWE", "123123656545");
		/* 12 */test("SSSWNNNE", "126546315");
		/* 13 */test("SWNWSSSWWE", "12415423646");
		/* 14 */test("ENNWWS", "1354135");
		/* 15 */test("ESWNNW", "1321365");
		/* 16 */test("NWSSE", "154135");
		/* 17 */test("SWNWEWSEEN", "12415154135");
		/* 18 */test("EWNWEEEEWN", "13154532426");
		/* 19 */test("WNEWEWWWSNW", "145151562421");
		/* 20 */test("NNEE", "15631");
		/* 21 */test("EEEEWNWSW", "1364145642");
		/* 22 */test("SENNWWES", "123142321");
		/* 23 */test("SWWWSNSNESWW", "1245363635631");
		/* 24 */test("WESSENSE", "141263231");
		/* 25 */test("SWNSSESESSS", "124146231562");
		/* 26 */test("ENS", "1353");
		/* 27 */test("WNN", "1453");
		/* 28 */test("SSEENEEEN", "1263124536");
		/* 29 */test("NWSNNNW", "15414632");
		/* 30 */test("ESSSSSWW", "132453215");
		/* 31 */test("ESE", "1326");
		/* 32 */test("SNWNWWNSSSS", "121456232453");
		/* 33 */test("SWEESEN", "12423653");
		/* 34 */test("NEEWNSSWWW", "15323631562");
		/* 35 */test("WSEW", "14212");
		/* 36 */test("SWSNNNSNWE", "12464131353");
		/* 37 */test("ENWEWSEEW", "1351513545");
		/* 38 */test("WSEWN", "142124");
		/* 39 */test("EWNEESEWE", "1315321414");
		/* 40 */test("NESEEN", "1531263");
		/* 41 */test("WSW", "1426");
		/* 42 */test("ENEWE", "135656");
	}
}