Submission #1171274

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Source Code Expand

// package atcoder.arc.arc070;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        in = new InputReader(System.in);
        out = new PrintWriter(System.out);

        int a = in.nextInt();
        int b = in.nextInt();
        if (a <= b) {
            out.println("Impossible");
            out.flush();
            return;
        }

        int n = a + b;
        if (n == 1) {
            out.println("! 1");
            out.flush();
            return;
        }

        map = new int[n][n];
        int[] co = new int[n+1];
        for (int i = 0; i < n ; i++) {
            if (question(i, (i+1)%n)) {
                co[i+1] = co[i] + 1;
            } else {
                co[i+1] = 0;
            }
        }

        int max = 0;
        int rightPerson = -1;
        for (int i = 1 ; i <= n ; i++) {
            if (max < co[i]) {
                max = co[i];
                rightPerson = i % n;
            }
        }

        StringBuilder ans = new StringBuilder();
        ans.append("! ");
        for (int i = 0; i < n ; i++) {
            ans.append(question(rightPerson, i) ? '1' : '0');
        }
        out.println(ans.toString());
        out.flush();
    }

    static InputReader in;
    static PrintWriter out;
    static int[][] map;

    static boolean question(int a, int b) {
        if (a == b) {
            return true;
        }
        if (map[a][b] == 0) {
            out.println(String.format("? %d %d", a, b));
            out.flush();
            char ret = in.nextToken().toCharArray()[0];
            map[a][b] = ret == 'Y' ? 1 : -1;
            return ret == 'Y';
        } else {
            return map[a][b] == 1;
        }
    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        private int[] nextInts(int n) {
            int[] ret = new int[n];
            for (int i = 0; i < n; i++) {
                ret[i] = nextInt();
            }
            return ret;
        }

        private int[][] nextIntTable(int n, int m) {
            int[][] ret = new int[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    ret[i][j] = nextInt();
                }
            }
            return ret;
        }

        private long[] nextLongs(int n) {
            long[] ret = new long[n];
            for (int i = 0; i < n; i++) {
                ret[i] = nextLong();
            }
            return ret;
        }

        private long[][] nextLongTable(int n, int m) {
            long[][] ret = new long[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    ret[i][j] = nextLong();
                }
            }
            return ret;
        }

        private double[] nextDoubles(int n) {
            double[] ret = new double[n];
            for (int i = 0; i < n; i++) {
                ret[i] = nextDouble();
            }
            return ret;
        }

        private int next() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public char nextChar() {
            int c = next();
            while (isSpaceChar(c))
                c = next();
            if ('a' <= c && c <= 'z') {
                return (char) c;
            }
            if ('A' <= c && c <= 'Z') {
                return (char) c;
            }
            throw new InputMismatchException();
        }

        public String nextToken() {
            int c = next();
            while (isSpaceChar(c))
                c = next();
            StringBuilder res = new StringBuilder();
            do {
                res.append((char) c);
                c = next();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public int nextInt() {
            int c = next();
            while (isSpaceChar(c))
                c = next();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = next();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c-'0';
                c = next();
            } while (!isSpaceChar(c));
            return res*sgn;
        }

        public long nextLong() {
            int c = next();
            while (isSpaceChar(c))
                c = next();
            long sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = next();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c-'0';
                c = next();
            } while (!isSpaceChar(c));
            return res*sgn;
        }

        public double nextDouble() {
            return Double.valueOf(nextToken());
        }

        public boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }

    static void debug(Object... o) {
        System.err.println(Arrays.deepToString(o));
    }
}

Submission Info

Judge Result