挑战程序竞赛系列（49）：4.2 推理与动态规划算法（2）

dp[i][j][k] 第i支队伍第k个人，剩余k个石子时，能否赢得当前轮

注意当k = 0，表明是必胜态，而当k = 1时，一定为必输态。

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main{

    String INPUT = "./data/judge/201709/P2068.txt";

    public static void main(String[] args) throws IOException {
        new Main().run();
    }

    static final int MAX_S = 1 << 13;
    boolean[][][] dp; //第k只队伍 第j个队员 剩余i个石头的状态

    void solve() {
        while (true) {
            int n = ni();
            if (n == 0) break;
            int s = ni();

            dp = new boolean[2][12][MAX_S + 16];

            int[] team = new int[2 * n];
            for (int i = 0; i < 2 * n; ++i) {
                team[i] = ni();
            }

            for (int i = 0; i < 2 * n; ++i) {
                dp[i & 1][i / 2 + 1][0] = true;
                dp[i & 1][i / 2 + 1][1] = false; // 必输态
            }

            for (int i = 2; i <= s; ++i) {
                for (int now = 0; now < 2 * n; ++now) {
                    int nxt = (now + 1) % (2 * n);
                    for (int j = team[now]; j >= 1; --j) {
                        if (i - j >= 0) {
                            dp[now & 1][now / 2 + 1][i] |= !dp[nxt & 1][nxt / 2 + 1][i - j];
                            if (dp[now & 1][now / 2 + 1][i]) break;
                        }
                    }
                }
            }

            out.println(dp[0][1][s] ? "1" : "0");
        }
    }

    FastScanner in;
    PrintWriter out;

    void run() throws IOException {
        boolean oj;
        try {
            oj = ! System.getProperty("user.dir").equals("F:\\java_workspace\\leetcode");
        } catch (Exception e) {
            oj = System.getProperty("ONLINE_JUDGE") != null;
        }

        InputStream is = oj ? System.in : new FileInputStream(new File(INPUT));
        in = new FastScanner(is);
        out = new PrintWriter(System.out);
        long s = System.currentTimeMillis();
        solve();
        out.flush();
        if (!oj){
            System.out.println("[" + (System.currentTimeMillis() - s) + "ms]");
        }
    }

    public boolean more(){
        return in.hasNext();
    }

    public int ni(){
        return in.nextInt();
    }

    public long nl(){
        return in.nextLong();
    }

    public double nd(){
        return in.nextDouble();
    }

    public String ns(){
        return in.nextString();
    }

    public char nc(){
        return in.nextChar();
    }

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;
        boolean hasNext;

        public FastScanner(InputStream is) throws IOException {
            br = new BufferedReader(new InputStreamReader(is));
            hasNext = true;
        }

        public String nextToken() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception e) {
                    hasNext = false;
                    return "##";
                }
            }
            return st.nextToken();
        }

        String next = null;
        public boolean hasNext(){
            next = nextToken();
            return hasNext;
        }

        public int nextInt() {
            if (next == null){
                hasNext();
            }
            String more = next;
            next = null;
            return Integer.parseInt(more);
        }

        public long nextLong() {
            if (next == null){
                hasNext();
            }
            String more = next;
            next = null;
            return Long.parseLong(more);
        }

        public double nextDouble() {
            if (next == null){
                hasNext();
            }
            String more = next;
            next = null;
            return Double.parseDouble(more);
        }

        public String nextString(){
            if (next == null){
                hasNext();
            }
            String more = next;
            next = null;
            return more;
        }

        public char nextChar(){
            if (next == null){
                hasNext();
            }
            String more = next;
            next = null;
            return more.charAt(0);
        }
    }
}