AdventOfCode/2017/16/solution.py

#!/bin/python3
import sys,re,collections

from pprint import pprint

sys.path.insert(0, '../../')
from fred import list2int

input_f = 'input'

part = 2
#########################################
#                                       #
#              Part 1                   #
#                                       #
#########################################

inst = []

programs = 'abcdefghijklmnop'
#programs = 'abcde'

def parse_input(input_str):
    pattern = r"^(s(\d+)|x(\d+)/(\d+)|p([a-zA-Z])/([a-zA-Z]))$"

    match = re.match(pattern, input_str)
    if match:
        if match.group(2):
            return ('s', int(match.group(2)))
        elif match.group(3) and match.group(4):
            return ('x', int(match.group(3)), int(match.group(4)))
        elif match.group(5) and match.group(6):
            return ('p', match.group(5), match.group(6))
    return None 
        
def swap_pos(d, index1, index2):
    if not (0 <= index1 < len(d)) or not (0 <= index2 < len(d)):
        raise IndexError("Index out of range")
    d[index1], d[index2] = d[index2], d[index1]

def swap_items(d, item1, item2):
    try:
        index1 = d.index(item1)
        index2 = d.index(item2)
            
        d[index1], d[index2] = d[index2], d[index1]
    except ValueError as e:
        raise ValueError(f"One or both items not found in deque: {e}")

if part == 1:
    with open(input_f) as file:
        for line in file:
            instructions = line.rstrip().split(',')
    
    programs = collections.deque(list(programs))

    #print(programs)
    #print(instructions)
    print(len(instructions))
    
    for idx,i in enumerate(instructions):
        inst = parse_input(i)
        print(idx,end=' ')
        #print(i)
        #rint(inst)
        if inst[0] == 's':
            #print('Spin', i)
            programs.rotate(inst[1])

        elif inst[0] == 'x':
            #print('Exchange',i)
            swap_pos(programs,inst[1],inst[2])

        elif inst[0] == 'p':
            #print('Partner',i)
            swap_items(programs,inst[1],inst[2])
        else:
            print(inst)
            input()
        
        

    for i in programs:
        print(i,end='')
    print()


#########################################
#                                       #
#              Part 2                   #
#                                       #
#########################################
if part == 2:
    
    start_value = list('abcdefghijklmnop')

    with open(input_f) as file:
        for line in file:
            instructions = line.rstrip().split(',')
    
    programs = collections.deque(list(programs))

    #print(programs)
    #print(instructions)
    #print(len(instructions))

    duplicates = []
    done = False
    indx = 0
    while not done:
        #print(r,list(programs))
        #input()
        for idx,i in enumerate(instructions):
            inst = parse_input(i)
            #print(idx,end=' ')
            #print(i)
            #rint(inst)
            if inst[0] == 's':
                #print('Spin', i)
                programs.rotate(inst[1])

            elif inst[0] == 'x':
                #print('Exchange',i)
                swap_pos(programs,inst[1],inst[2])

            elif inst[0] == 'p':
                #print('Partner',i)
                swap_items(programs,inst[1],inst[2])
            else:
                print(inst)
                input()


            if start_value == list(programs):
                #print(start_value)
                #print(list(programs))
                done = True
        duplicates.append(list(programs))
        
        indx += 1
        

    print(''.join(duplicates[(1000000000%indx)-1]))