OJ Board

Code: Select all

now i know why i got WA :)
}

Code: Select all

import java.io.IOException;
import java.util.StringTokenizer;

class Main {
	int[] b = new int[110];
	void work() {
		String line;
		StringTokenizer st;
		int tc = 1;
		while ((line = readLine()) != null) {
			if (line.length() == 0)
				continue;
			int n = parseInt(line);
			line = readLine();
			while (line.length() == 0)
				line = readLine();
			st = new StringTokenizer(line);
			for (int i = 0; i < n; i++) {
				b[i] = parseInt(st.nextToken());
			}
			boolean[] seen = new boolean[20020];
			boolean ok = true;
			if (b[0] < 1)
				ok = false;
			if (ok) {
				for (int i = 0; i < n; i++) {
					if (b[i] > 10000 || (i < n - 1 && b[i] >= b[i + 1])) {
						ok = false;
						break;
					}
					for (int j = i; j < n; j++) {
						int sum = b[i] + b[j];
						if (seen[sum]) {
							ok = false;
							break;
						}
						seen[sum] = true;
					}
					if (!ok)
						break;
				}
			}
			if (ok) {
				System.out.println("Case #" + (tc++)
						+ ": It is a B2-Sequence.\n");
			} else {
				System.out.println("Case #" + (tc++)
						+ ": It is not a B2-Sequence.\n");
			}
		}
	}

	private String readLine() {
		StringBuffer sb = new StringBuffer();
		int b = 0;
		while (b != '\n' && b >= 0) {
			try {
				b = System.in.read();
			} catch (IOException e) {
				return null;
			}
			if (b != '\r' && b != '\n' && b >= 0)
				sb.append((char) b);
		}
		if (sb.length() == 0 && b < 0)
			return null;
		return sb.toString().trim();
	}

	private int parseInt(String s) {
		// what if s.length() == 0 ?
		int result = 0;
		int sign = (s.charAt(0) == '-') ? -1 : 1;
		if (sign == -1)
			s = s.substring(1);
		if (s.charAt(0) == '+')
			s = s.substring(1);
		int i = 0, max = s.length();
		if (max > 0) {
			while (i < max) {
				result *= 10;
				result += s.charAt(i++) - 48;
			}
		}
		return sign * result; // could be 0 if not an integer
	}

	public static void main(String args[]) {
		Main myWork = new Main();
		myWork.work();
	}
}