第2回 オフラインリアルタイムどう書く: Java解答

BitTetris.java

package yhpg2;

import static org.junit.Assert.assertEquals;

import java.util.*;

import org.junit.Test;

/**
 * 問題: http://nabetani.sakura.ne.jp/hena/ord2/
 */
public class BitTetris {

	String execute(String input) {
		String[] split = input.split("-");
		String[] cols = getCols(split);
		String[] rows = _tr(cols);

		List<Integer> deleteIndexes = getDeleteIndexes(rows);
		String[] deleted = getDeleted(rows, deleteIndexes);

		String[] result = new String[deleted.length];
		result = _tr(deleted);
		result = _tr(result);
		result = _tr(result);
		String resultStr = getResultStr(result);
		return resultStr;
	}

	String toData(String hexStr) {
		String binStr = Integer.toBinaryString(Integer.parseInt(hexStr, 16));
		Formatter f = new Formatter();
		f.format("%04d", Integer.parseInt(binStr));
		return f.toString();
	}

	String[] getDeleted(String[] rows, List<Integer> deleteRowList) {
		String[] clone = new String[rows.length + 1];
		for (int i = 0; i < rows.length; i++) {
			clone[i] = rows[i];
		}
		clone[clone.length - 1] = "00000000";

		String[] tmp = new String[rows.length - deleteRowList.size()];
		int cnt = 0;
		for (int i : deleteRowList) {
			for (int k = i - cnt; k < rows.length; k++) {
				clone[k] = clone[k + 1];
			}
			cnt++;
		}

		for (int i = 0; i < tmp.length; i++) {
			tmp[i] = clone[i];
		}
		return tmp;
	}

	boolean canDelete(String row) {
		if (row.indexOf("0") == -1) {
			return true;
		}
		return false;
	}

	String getResultStr(String[] result) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < result.length; i++) {
			Formatter f = new Formatter();
			f.format("%08d", Integer.parseInt(result[i]));
			String string = f.toString();
			sb.append(Integer.toHexString(Integer.valueOf(
					string.substring(0, 4), 2)));
			sb.append(Integer.toHexString(Integer.valueOf(
					string.substring(4, 8), 2)));
			sb.append("-");
		}
		sb.deleteCharAt(sb.length() - 1);
		return new String(sb);
	}

	String[] getCols(String[] split) {
		String[] result = new String[split.length];
		for (int i = 0; i < split.length; i++) {
			String data = "";
			for (int k = 0; k < 2; k++) {
				data += toData(String.valueOf(split[i].charAt(k)));
			}
			result[i] = data;
		}
		return result;
	}

	List<Integer> getDeleteIndexes(String[] rows) {
		List<Integer> result = new ArrayList<>();
		for (int i = 0; i < rows.length; i++) {
			if (canDelete(rows[i])) {
				result.add(i);
			}
		}
		return result;
	}

	String[] _tr(String[] str) {
		String[] result = new String[str[0].length()];
		for (int i = 0; i < result.length; i++) {
			for (int k = 0; k < str.length; k++) {
				if (result[i] == null) {
					result[i] = String.valueOf(str[k].charAt(i));
				} else {
					String s = result[i];
					result[i] = s + String.valueOf(str[k].charAt(i));
				}
			}
		}
		return result;
	}

	public static void main(String[] args) {
		BitTetris tet = new BitTetris();
		System.out.println(tet.execute("ff-2f-23-f3-77-7f-3b"));
	}

	@Test
	public void testExecute() throws Exception {
		BitTetris tet = new BitTetris();

		assertEquals("1f-03-00-1c-0d-0f-06",
				tet.execute("ff-2f-23-f3-77-7f-3b"));
		assertEquals("00", tet.execute("01"));
		assertEquals("00", tet.execute("00"));
		assertEquals("0c-02", tet.execute("7a-4e"));
		assertEquals("08-14", tet.execute("56-b6"));
		assertEquals("00-00-00", tet.execute("12-12-12"));
		assertEquals("0a-0f-05", tet.execute("de-ff-7b"));
		assertEquals("05-1e-20", tet.execute("95-be-d0"));
		assertEquals("1c-20-2b", tet.execute("7c-b0-bb"));
		assertEquals("3a-56-11-2a", tet.execute("7a-b6-31-6a"));
		assertEquals("18-06-11-40", tet.execute("32-0e-23-82"));
		assertEquals("0f-07-0b-0d-0e", tet.execute("ff-7f-bf-df-ef"));
		assertEquals("35-5f-5c-2e-02", tet.execute("75-df-dc-6e-42"));
		assertEquals("22-11-6f-47-78", tet.execute("62-51-ef-c7-f8"));
		assertEquals("04-23-46-6d-2d-0b", tet.execute("0c-47-8e-dd-5d-17"));
		assertEquals("52-28-2b-35-4f-0f", tet.execute("aa-58-5b-6d-9f-1f"));
		assertEquals("0f-00-08-04-02-01", tet.execute("ff-55-d5-75-5d-57"));
		assertEquals("7e-7d-7b-77-6f-5f-3f",
				tet.execute("fe-fd-fb-f7-ef-df-bf"));
		assertEquals("7e-7d-7b-77-6f-5f-3f",
				tet.execute("fd-fb-f7-ef-df-bf-7f"));
		assertEquals("69-05-55-67-0b-4f-6e",
				tet.execute("d9-15-b5-d7-1b-9f-de"));
		assertEquals("18-05-7d-20-00-46-5a",
				tet.execute("38-15-fd-50-10-96-ba"));
		assertEquals("fe-fd-fb-f7-ef-df-bf-7f",
				tet.execute("fe-fd-fb-f7-ef-df-bf-7f"));
	}
}