第23回オフラインリアルタイムどう書くのJava解答（別解）

SnakemonicNotParse.java

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

import org.junit.Test;

/**
 * http://nabetani.sakura.ne.jp/hena/ord23snakemoinc/
 */
public class SnakemonicNotParse {

	private static final String PADDING = "//////";

	public String solve(final String input) {
		String line = PADDING + input + PADDING;
		List<Integer> result = new ArrayList<>();
		for (int i = PADDING.length(); i < line.length() - PADDING.length(); i++) {
			result = find(line, i, 1, result);
		}
		return String.valueOf(Collections.max(result));
	}

	List<Integer> find(final String line, final int index, final int cnt,
			final List<Integer> list) {
		List<Integer> result = new ArrayList<>(list);
		if (Character.isDigit(line.charAt(index)) == false) {
			result.add(cnt);
			return result;
		}
		if (isTarget(line, index, PADDING.length() * -1)) {
			result = find(line, index - PADDING.length(), cnt + 1, result);
		}
		if (isTarget(line, index, 1)) {
			result = find(line, index + 1, cnt + 1, result);
		}
		if (isTarget(line, index, PADDING.length())) {
			result = find(line, index + PADDING.length(), cnt + 1, result);
		}
		if (isTarget(line, index, -1)) {
			result = find(line, index - 1, cnt + 1, result);
		}
		result.add(cnt);
		return result;
	}

	boolean isTarget(final String line, final int index, final int adj) {
		return Character.isDigit(line.charAt(index + adj))
				&& line.charAt(index) < line.charAt(index + adj);
	}

	@Test
	public void testSnakemonicNotParse() throws Exception {
		/* 0 */test("01224/82925/69076/32298/21065", "6");
		/* 1 */test("03478/12569/03478/12569/03478", "10");
		/* 2 */test("09900/28127/87036/76545/87650", "10");
		/* 3 */test("77777/77777/77777/77777/77777", "1");
		/* 4 */test("00000/11111/22222/33333/44444", "5");
		/* 5 */test("01234/12345/23456/34567/45678", "9");
		/* 6 */test("10135/21245/43456/55567/77789", "8");
		/* 7 */test("33333/33333/55555/55555/77777", "2");
		/* 8 */test("01234/11234/22234/33334/44444", "5");
		/* 9 */test("98765/88765/77765/66665/55555", "5");
		/* 10 */test("01234/10325/23016/32107/45670", "8");
		/* 11 */test("34343/43434/34343/43434/34343", "2");
		/* 12 */test("14714/41177/71141/17414/47141", "3");
		/* 13 */test("13891/31983/89138/98319/13891", "4");
		/* 14 */test("01369/36901/90136/13690/69013", "5");
		/* 15 */test("02468/24689/46898/68986/89864", "6");
		/* 16 */test("86420/68642/46864/24686/02468", "5");
		/* 17 */test("77777/75557/75357/75557/77777", "3");
		/* 18 */test("53135/33133/11111/33133/53135", "3");
		/* 19 */test("01356/23501/45024/61246/13461", "5");
		/* 20 */test("46803/68025/91358/34792/78136", "4");
		/* 21 */test("66788/56789/55799/43210/33211", "9");
		/* 22 */test("40000/94321/96433/97644/98654", "9");
		/* 23 */test("58950/01769/24524/24779/17069", "6");
		/* 24 */test("97691/01883/98736/51934/81403", "4");
		/* 25 */test("92049/27798/69377/45936/80277", "5");
		/* 26 */test("97308/77113/08645/62578/44774", "5");
		/* 27 */test("90207/17984/01982/31272/60926", "6");
		/* 28 */test("62770/65146/06512/15407/89570", "4");
		/* 29 */test("93914/46889/27554/58581/18703", "5");
		/* 30 */test("42035/12430/60728/30842/90381", "5");
		/* 31 */test("90347/53880/67954/95256/68777", "6");
		/* 32 */test("05986/60473/01606/16425/46292", "5");
		/* 33 */test("18053/90486/24320/04250/03853", "5");
		/* 34 */test("36865/13263/67280/18600/12774", "5");
		/* 35 */test("72456/72052/79971/14656/41151", "5");
		/* 36 */test("94888/28649/05561/76571/97567", "5");
		/* 37 */test("50214/94693/88718/78922/55359", "5");
		/* 38 */test("76502/99325/17987/31737/93874", "7");
		/* 39 */test("87142/14764/13014/00248/73105", "6");
		/* 40 */test("24573/71679/48704/19786/91834", "7");
		/* 41 */test("20347/61889/06074/61263/20519", "7");
		/* 42 */test("74344/97459/97302/14439/35689", "6");
		/* 43 */test("04794/52198/50294/09340/24160", "5");
		/* 44 */test("41065/69344/64698/54167/43348", "7");
		/* 45 */test("39947/15696/03482/19574/70235", "7");
		/* 46 */test("92767/16790/84897/69765/75734", "7");
		/* 47 */test("09654/79610/05070/23456/74687", "8");
		/* 48 */test("73998/98799/98707/05633/23915", "8");
		/* 49 */test("35661/17480/89723/64335/27217", "7");
		/* 50 */test("02489/77571/84873/03879/84460", "7");
	}

	private void test(String input, String expected) {
		SnakemonicNotParse target = new SnakemonicNotParse();
		// assertEquals(expected, target.solve(input));
		String actual = target.solve(input);
		System.out.println(actual.equals(expected) ? "ok" : "****NG**** "
				+ input + " -> " + expected + ", but " + actual);
	}
}