gistfile1.py

#Reversal Distance
dataset = open('rosalind_rear_sample.txt','r')
data = dataset.read().split('\n')
dataset.close()
while len(data)>(len(data)-data.count('')):
	data.remove('')
originals = [[int(x) for x in y.split()] for y in data[::2]]
perms = [[int(x) for x in y.split()] for y in data[1::2]]
def findBreak(perm):
	num = 0
	brkptspots = []
	for index in range(len(perm)-1):
		breakpoint = abs(perm[index+1]-perm[index])
		if index+1==len(perm)-1 and breakpoint!=1:
			num+=1
			brkptspots.append(index),brkptspots.append(index+1)
		elif breakpoint!=1:
			num+=1       
			brkptspots.append(index)
	return num, brkptspots
def possRev(perm):
	revs = []
	bpis = []
	bpi,brkpts=findBreak(perm)
	for first in brkpts:
		for second in brkpts[brkpts.index(first)+1:]:
			if first==0:
				continue
			elif second-first==1:
				continue
			else:
				perm[first:second]=reversed(perm[first:second])
				checkBpi(perm,bpi,revs,bpis)
				perm[first:second]=reversed(perm[first:second])
	mBpi=min(bpis)
	if len(revs)==0:
		return None
	else:
		return pruneRevs(revs,mBpi)
def flatten(reversals):
	lst=[]
	for rev in reversals: lst.extend(rev)
	return lst
def pruneRevs(reversals,mBpi):
	revs = []
	totRevs = []
	for rev in reversals:
		if findBreak(rev)[0]==mBpi:
			revs.append(rev)
	return revs
def checkBpi(perm,bpi,revs,bpis):
	bpi2=findBreak(perm)[0]
	if bpi-bpi2==2:
		revs.append(perm[:])
		bpis.append(bpi2)
	elif bpi-bpi2==1:
		revs.append(perm[:])
		bpis.append(bpi2)
	elif bpi-bpi2==0:
		revs.append(perm[:])
		bpis.append(bpi2)
s = perms[3][:]
s.insert(0,0),s.append(11)
count=1
s=possRev(s)
w=[0,1,2,3,4,5,6,7,8,9,10,11]
q=[4,3,2,1,8,9,10,7,6,5]
out = open('rosalind_rear_out.txt','w')
out.close()