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 (Python):
from collections import deque
import sys
readline = sys.stdin.readline
write = sys.stdout.write
def solve():
    N, M, P = map(int, readline().split())
    G = [[] for i in range(N)]
    for i in range(M):
        u, v = map(int, readline().split())
        G[u-1].append(v-1)
        G[v-1].append(u-1)
    N1 = 1 << N
    bc = [0]*N1
    for i in range(1, N1):
        bc[i] = bc[i ^ (i & -i)] + 1
    ec = [0]*N1
    for state in range(1, N1):
        c = 0
        for v in range(N):
            if (state & (1 << v)) == 0:
                continue
            for w in G[v]:
                if (state & (1 << w)) == 0:
                    continue
                c += 1
        ec[state] = c >> 1
    N0 = 1 << (N-1)
    dp = [0]*N1
    dp[1] = 1
    for s0 in range(1, N0):
        state0 = (s0 << 1) | 1
        state1 = (state0-1) & state0
        v = 0
        while state1:
            if state1 & 1:
                k = ec[state0] - ec[state1] - ec[state0 ^ state1]
                v += dp[state1] * (P/100)**k
            state1 = (state1 - 1) & state0
        dp[state0] = 1 - v
    write("%.16f\n" % dp[N1-1])
solve()