Problem:
Network Reliability

An undirected graph is given.
Each edge of the graph disappears with a constant probability.
Calculate the probability with which the remained graph is connected.

Input

The first line contains three integers N (1 \leq N \leq 14), M (0 \leq M \leq 100) and P (0 \leq P \leq 100), separated by a single space.
N is the number of the vertices and M is the number of the edges. P is the probability represented by a percentage.

The following M lines describe the edges.
Each line contains two integers v_i and u_i (1 \leq u_i, v_i \leq N).
(u_i, v_i) indicates the edge that connects the two vertices u_i and v_i.

Output

Output a line containing the probability with which the remained graph is connected.
Your program may output an arbitrary number of digits after the decimal point. However, the absolute error should be 10^{-9} or less.

Sample Input 1

3 3 50
1 2
2 3
3 1

Output for the Sample Input 1

0.500000000000

Sample Input 2

3 3 10
1 2
2 3
3 1

Output for the Sample Input 2

0.972000000000

Sample Input 3

4 5 50
1 2
2 3
3 4
4 1
1 3

Output for the Sample Input 3

0.437500000000

Solution in C# (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
//using System.Numerics;
//using Point = System.Numerics.Complex;
using Number = System.Int64;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var m = sc.Integer();
            var p = sc.Integer() / 100.0;
            var a = new int[m];
            var b = new int[m];
            var E = new int[1 << n];
            for (int i = 0; i < m; i++)
            {
                a[i] = sc.Integer() - 1;
                b[i] = sc.Integer() - 1;
                for (int j = 0; j < 1 << n; j++)
                    if (((j >> a[i]) & 1) == 1 && ((j >> b[i] & 1) == 1)) E[j]++;
            }
            var dp = new double[1 << n];
            for (int i = 0; i < 1 << n; i++)
                dp[i] = -1;
            Func<int, double> dfs = null;
            dfs = s =>
              {
                  if (dp[s] > -0.5) return dp[s];
                  var ret = 1.0;
                  var min = s & -s;
                  for (int sub = (s - 1) & s; sub > 0; sub = (sub - 1) & s)
                  {
                      if (min != (sub & -sub)) continue;
                      ret -= dfs(sub) * Math.Pow(p, E[s] - E[sub] - E[s ^ sub]);
                  }
                  return dp[s] = ret;
              };
            IO.Printer.Out.WriteLine("{0:0.000000000000}", dfs((1 << n) - 1));
        }

        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    //static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    //static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer: StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion