Submission #342258

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Source Code Expand

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;

class Myon
{
    public Myon() { }
    public static int Main()
    {
        new Myon().calc();
        return 0;
    }

    Dictionary<long, int> dic;

    void calc()
    {
        Scanner cin = new Scanner();
        int A = cin.nextInt();
        int B = cin.nextInt();
        int C = cin.nextInt();
        int[] a = new int[A];
        int[] b = new int[B];
        for (int i = 0; i < A; i++)
        {
            a[i] = cin.nextInt();
        }

        for (int i = 0; i < B; i++)
        {
            b[i] = cin.nextInt();
        }

        //何番目のカードまで見たか、対象のカードの前にいくつあるか

        double[,] dp = new double[B + 1, B + 1]; 
        dp[0, 0] = a.Sum();

        for (int i = 0; i < B; i++)
        {
            for (int j = 0; j < B; j++)
            {
                int ok = j + 1;
                int ng = 1 + C + i + 1 - ok;
                dp[i + 1, j + 1] += dp[i, j] * b[i] * ok / (ok + ng);
                dp[i + 1, j] += dp[i, j] * ng / (ok + ng);
            }
        }

        double ret = 0;
        for (int i = 0; i <= B; i++)
        {
            ret += dp[B, i];
        }
        Console.WriteLine("{0:0.00000000000000000}", ret / (1 + C));
    }

}




class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        i = 0;
        return s[i++];
    }

    public int nextInt()
    {
        return int.Parse(next());
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }

}


class XRand
{
    uint x, y, z, w;


    public XRand()
    {
        init();
    }

    public XRand(uint s)
    {
        init();
        init_xor128(s);
    }

    void init()
    {
        x = 314159265; y = 358979323; z = 846264338; w = 327950288;

    }

    public void init_xor128(uint s)
    {
        z ^= s;
        z ^= z >> 21; z ^= z << 35; z ^= z >> 4;
        z *= 736338717;
    }

    uint next()
    {
        uint t = x ^ x << 11; x = y; y = z; z = w; return w = w ^ w >> 19 ^ t ^ t >> 8;
    }

    public long nextLong(long m)
    {
        return (long)((((ulong)next() << 32) + next()) % (ulong)m);
    }

    public int nextInt(int m)
    {
        return (int)(next() % m);
    }

    public long nextLong(long min, long max)
    {
        return min + nextLong(max - min + 1);
    }

    public int nextInt(int min, int max)
    {
        return min + nextInt(max - min + 1);
    }

    public int nextIntP(int a)
    {
        return (int)Math.Pow(a, nextDouble());
    }

    public int nextIntP(int min, int max)
    {
        int diff = max - min;
        return min + nextIntP(diff + 2) - 1;
    }

    public long nextLongP(long a)
    {
        return (long)Math.Pow(a, nextDouble());
    }

    public long nextLongP(long min, long max)
    {
        long diff = max - min;
        return min + nextLongP(diff + 2) - 1;
    }


    public double nextDouble()
    {
        return (double)next() / uint.MaxValue;
    }

    public double nextDoubleP(double a)
    {
        return Math.Pow(a, nextDouble());
    }
}

Submission Info

Judge Result