Mine

from sys import stdinfrom decimal import *def besokNode(nabomatrise, node, nodeIkkeBesokt, kanter, noder, n):		nodeIkkeBesokt[node] = False	noder -= 1		for i in xrange(0,n):		if nabomatrise[i][node]:			kanter -=1		if nabomatrise[node][i]:			if nodeIkkeBesokt[i]:				kanter, noder = besokNode(nabomatrise, i, nodeIkkeBesokt, kanter, noder, n)		return (kanter, noder)	def main():	n = int(stdin.readline())	nabomatrise = [None] * n # rader	tK = 0	for i in xrange(0, n):		nabomatrise[i] = [False] * n # kolonner		linje = stdin.readline()		for j in xrange(0, n):			if linje[j] == '1':				tK +=1				nabomatrise[i][j] = True	for startnoden in stdin:				noder = n		kanter = tK				nodeIkkeBesokt = []		nodeIkkeBesokt = [True] * n				startnode = int(startnoden)				kanter, noder = besokNode(nabomatrise, startnode, nodeIkkeBesokt, kanter, noder, n)				if noder == 0:			print "0.000"		else:			print "%.3f" % ((float(kanter) / float(noder**2)) + 1E-12)main()