Solution to Day 16: Permutation Promenade - Part 2

advent_of_code_d16_p2.py

#aoc_d16.py
import re
inp = 'abcde'
inp = ''.join([chr(c+ord('a')) for c in range(0,16)])
moves = open('input_d16.txt','r').read().split(',')

def rotate(l, n):
    return l[-n:] + l[:-n]

def dance(inp, moves):
	for i in moves:
		if i.startswith("s"):
			much = int(i.replace('s',''))
			inp = rotate(inp, much)
		if i.startswith("x"):
			m = re.match("x(\d+)/(\d+)",i)
			c1 = int(m.group(1))
			c2 = int(m.group(2))
			d = [c for c in inp]
			#print i,c1
			t = d[c1]
			d[c1] = d[c2]
			d[c2] = t
			inp = ''.join(d)
		if i.startswith("p"):
			m = re.match("p([a-p]+)/([a-p]+)",i)
			e1 = m.group(1)
			c1 = inp.index(e1)
			e2 = m.group(2)
			c2 = inp.index(e2)
			d = [c for c in inp]
			t = d[c1]
			d[c1] = d[c2]
			d[c2] = t
			inp = ''.join(d)


	return inp

for k in range(1000000000):
	inp = dance(inp, moves)
print inp