第9回オフラインリアルタイムどう書く（Java解答）の別解

BusfeeEx.java

package yhpg9;

import static org.junit.Assert.assertEquals;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

import org.junit.Test;

class Paseenger {
  Age age;
	Kind kind;

	public Paseenger(final String str) {
		age = createAge(str.charAt(0));
		kind = createKind(str.charAt(1));
	}

	private Age createAge(final char c) {
		AgeKey key = AgeKey.valueOf(String.valueOf(c));
		return key.make();
	}

	private Kind createKind(final char c) {
		KindKey key = KindKey.valueOf(String.valueOf(c));
		return key.make();
	}

	public void lineUp(final BusfeeEx bf) {
		age.lineUp(this, bf);
	}

	public int getFee(final int base) {
		int tmp = age.getFee(base);
		return kind.discount(tmp);
	}
}

abstract class Age {
	abstract int getFee(final int base);

	abstract void lineUp(final Paseenger p, final BusfeeEx bf);
}

class Adult extends Age {
	@Override
	public int getFee(final int base) {
		return base;
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		bf.pushPassenger(this, p);
	}
}

class Child extends Age {
	@Override
	public int getFee(final int base) {
		return BusfeeEx.getHalf(base);
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		bf.pushPassenger(this, p);
	}
}

class Infant extends Age {
	@Override
	public int getFee(final int base) {
		return BusfeeEx.getHalf(base);
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		p.kind.lineUp(p, bf);
	}
}

enum AgeKey {
	A {
		@Override
		Age make() {
			return new Adult();
		}
	},
	C {
		@Override
		Age make() {
			return new Child();
		}
	},
	I {
		@Override
		Age make() {
			return new Infant();
		}
	};

	abstract Age make();
}

abstract class Kind {
	abstract int discount(final int original);

	abstract void lineUp(final Paseenger p, final BusfeeEx bf);
}

class Normal extends Kind {
	@Override
	public int discount(final int original) {
		return original;
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		bf.pushPassenger(this, p);
	}
}

class Pass extends Kind {
	@Override
	public int discount(final int original) {
		return 0;
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		bf.pushPassenger(this, p);
	}
}

class Welfare extends Kind {
	@Override
	public int discount(final int original) {
		return BusfeeEx.getHalf(original);
	}

	@Override
	void lineUp(final Paseenger p, final BusfeeEx bf) {
		bf.pushPassenger(this, p);
	}
}

enum KindKey {
	n {
		@Override
		Kind make() {
			return new Normal();
		}
	},
	p {
		@Override
		Kind make() {
			return new Pass();
		}
	},
	w {
		@Override
		Kind make() {
			return new Welfare();
		}
	};

	abstract Kind make();
}

/**
 * 問題: http://nabetani.sakura.ne.jp/hena/ord9busfare/
 */
public class BusfeeEx {

	List<Paseenger> adults = new ArrayList<>();
	List<Paseenger> children = new ArrayList<>();
	List<Paseenger> infantNormal = new ArrayList<>();
	List<Paseenger> infantPass = new ArrayList<>();
	List<Paseenger> infantWelfare = new ArrayList<>();

	static int getHalf(final int original) {
		int tmp = original / 2;
		if (tmp % 10 == 0) {
			return tmp;
		}
		return tmp + (10 - tmp % 10);
	}

	List<Paseenger> createPassengers(final String str) {
		List<String> tmp = Arrays.asList(str.split(","));
		List<Paseenger> result = new ArrayList<>();
		for (String each : tmp) {
			result.add(new Paseenger(each));
		}
		return result;
	}

	public void pushPassenger(final Adult age, final Paseenger p) {
		adults.add(p);
	}

	public void pushPassenger(final Child age, final Paseenger p) {
		children.add(p);
	}

	public void pushPassenger(final Normal kind, final Paseenger p) {
		infantNormal.add(p);
	}

	public void pushPassenger(final Pass kind, final Paseenger p) {
		infantPass.add(p);
	}

	public void pushPassenger(final Welfare kind, final Paseenger p) {
		infantWelfare.add(p);
	}

	public String solve(final String input) {
		int base = Integer.valueOf(input.split(":")[0]);
		List<Paseenger> passengers = createPassengers(input.split(":")[1]);
		for (Paseenger each : passengers) {
			each.lineUp(this);
		}

		int freeLimit = adults.size() * 2;
		freeLimit = discount(infantNormal, freeLimit);
		discount(infantWelfare, freeLimit);

		passengers.clear();
		passengers.addAll(adults);
		passengers.addAll(children);
		passengers.addAll(infantNormal);
		passengers.addAll(infantPass);
		passengers.addAll(infantWelfare);

		int result = 0;
		for (Paseenger each : passengers) {
			result += each.getFee(base);
		}
		return String.valueOf(result);
	}

	private int discount(List<Paseenger> list, final int freeLimit) {
		int result = freeLimit;
		Iterator<Paseenger> iterator = list.iterator();
		while (iterator.hasNext()) {
			iterator.next();
			if (0 < result) {
				iterator.remove();
				result--;
			}
		}
		return result;
	}

	private void test(final String input, final String expected) {
		Busfee bf = new Busfee();
		assertEquals(expected, bf.solve(input));
	}

	@Test
	public void testBusfee() throws Exception {
		/* 0 */test("210:Cn,In,Iw,Ap,Iw", "170");
		/* 1 */test("220:Cp,In", "110");
		/* 2 */test("230:Cw,In,Iw", "240");
		/* 3 */test("240:In,An,In", "240");
		/* 4 */test("250:In,In,Aw,In", "260");
		/* 5 */test("260:In,In,In,In,Ap", "260");
		/* 6 */test("270:In,An,In,In,Ip", "410");
		/* 7 */test("280:Aw,In,Iw,In", "210");
		/* 8 */test("200:An", "200");
		/* 9 */test("210:Iw", "60");
		/* 10 */test("220:Ap", "0");
		/* 11 */test("230:Cp", "0");
		/* 12 */test("240:Cw", "60");
		/* 13 */test("250:In", "130");
		/* 14 */test("260:Cn", "130");
		/* 15 */test("270:Ip", "0");
		/* 16 */test("280:Aw", "140");
		/* 17 */test("1480:In,An,In,In,In,Iw,Cp,Cw,In,Aw,In,In,Iw,Cn,Aw,Iw",
				"5920");
		/* 18 */test("630:Aw,Cw,Iw,An,An", "1740");
		/* 19 */test("340:Cn,Cn,Ip,Ap", "340");
		/* 20 */test("240:Iw,Ap,In,Iw,Aw", "120");
		/* 21 */test("800:Cw,An,Cn,Aw,Ap", "1800");
		/* 22 */test("1210:An,Ip,In,Iw,An,Iw,Iw,An,Iw,Iw", "3630");
		/* 23 */test("530:An,Cw,Cw", "810");
		/* 24 */test("170:Aw,Iw,Ip", "90");
		/* 25 */test("150:In,Ip,Ip,Iw,In,Iw,Iw,In,An,Iw,Aw,Cw,Iw,Cw,An,Cp,Iw",
				"580");
		/* 26 */test("420:Cn,Cw,Cp", "320");
		/* 27 */test("690:Cw,In,An,Cp,Cn,In", "1220");
		/* 28 */test("590:Iw,Iw,Cn,Iw,Aw,In,In,Ip,Iw,Ip,Aw", "1200");
		/* 29 */test("790:Cw,Cn,Cn", "1000");
		/* 30 */test("1220:In,In,An,An,In,Iw,Iw,In,In,Ip,In,An,Iw", "4590");
		/* 31 */test("570:Cw,Cn,Cp", "440");
		/* 32 */test("310:Cn,Cw,An,An,Iw,Cp,Cw,Cn,Iw", "1100");
		/* 33 */test("910:Aw,In,Iw,Iw,Iw,Iw,Iw,An,Cw,In", "2290");
		/* 34 */test("460:Iw,Cw,Cw,Cn", "590");
		/* 35 */test("240:Iw,Iw,In,Iw,In,In,Cn,In,An", "780");
		/* 36 */test("1240:In,In,In,Ap,In,Cw,Iw,Iw,Iw,Aw,Cw", "2170");
		/* 37 */test(
				"1000:Iw,Ip,In,An,In,In,In,An,In,Iw,In,In,Iw,In,Iw,Iw,Iw,An",
				"5500");
		/* 38 */test("180:In,Aw,Ip,Iw,In,Aw,In,Iw,Iw,In", "330");
		/* 39 */test("440:In,Ip,Cp,Aw,Iw,In,An", "660");
		/* 40 */test("1270:Ap,In,An,Ip,In,Ip,Ip", "1270");
	}
}