cipher_sherlock.java

第四届百度杯预赛解题报告 武汉大学20090315

import java.util.*;
import java.io.*;

public class playfair {

	static final int maxSize = 1000;

	static Scanner in = new Scanner(System.in);
	
	static char board[][] = new char[5][5];
	static char que[]	  =	new char[maxSize];
	static boolean done[] = new boolean[30];

	public static void main(String args[]) throws Exception {
		int test_num = in.nextInt();
		in.nextLine();
		while (test_num -- > 0) {
			String buf = in.nextLine();
			int x = 0, y = 0;
			int len = buf.length();
			for (int i = 0; i < 26; i++) {
				done[i] = false;
			}
			done[9] = true;
			for (int i = 0; i < len; i++) {
				int c = 0;
				if (buf.charAt(i) == ' ')
					continue;
				if (buf.charAt(i) >= 'a' && buf.charAt(i) <= 'z') {
					c = buf.charAt(i) - 'a';
				} else {
					c = buf.charAt(i) - 'A';
				}
				if (c == 9)
					c = 8;
				if (done[c])
					continue;
				done[c] = true;
				board[x][y] = (char) ('A' + c);
				y ++;
				if (y == 5) {
					y = 0;
					x++;
				}
			}
			for (int i = 0; i < 26; i++)
				if (!done[i]) {
					board[x][y] = (char) ('A' + i);
					y ++;
					if (y == 5) {
						y = 0;
						x++;
					}
				}
			
			buf = in.nextLine();
			len = buf.length();
			int n = 0;
			for (int i = 0; i < len; i++) {
				if (buf.charAt(i) == ' ')
					continue;
				int c = 0;
				if (buf.charAt(i) >= 'a' && buf.charAt(i) <= 'z')
					c = buf.charAt(i) - 'a';
				else
					c = buf.charAt(i) - 'A';
				if (c == 9)
					c = 8;
				if (n > 0 && que[n - 1] == (char) ('A' + c))
					que[n ++] = 'X';
				que[n ++] = (char) ('A' + c);
			}
			if (n % 2 != 0)
				que[n ++] = 'X';

			for (int i = 0; i < n; i += 2) {
				int x1 = 0, x2 = 0, y1 = 0, y2 = 0;
				char a = que[i];
				char b = que[i + 1];
				for (int u = 0; u < 5; u ++)
					for (int v = 0; v < 5; v++)
						if (board[u][v] == a) {
							x1 = u;
							y1 = v;
						} else if (board[u][v] == b) {
							x2 = u;
							y2 = v;
						}
				if (x1 != x2 && y1 != y2) {
					System.out.print(board[x1][y2]);
					System.out.print(board[x2][y1]);
				}
				else 
					if (x1 == x2) {
						System.out.print(board[x1][(y1 + 1) % 5]);
						System.out.print(board[x2][(y2 + 1) % 5]);
					}
					else {
						System.out.print(board[(x1 + 1) % 5][y1]);
						System.out.print(board[(x2 + 1) % 5][y2]);
					}
			}
			System.out.println();
		}
	}
}