Advent of Code 2015 - Day 6 Solution - Python 3

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

mem_banks = [14, 0, 15, 12, 11, 11, 3, 5, 1, 6, 8, 4, 9, 1, 8, 4]


def increaseblk(idx):
    global mem_banks
    mem_banks[idx] += 1


def join_ints(a_list):
    return int(''.join(map(str, a_list)))


previous_states = [join_ints(mem_banks)]
cycles = 0

while True:
    max_block = max(mem_banks)
    tgt = mem_banks.index(max_block)
    iter_ = list(range(tgt+1, 16)) + list(range(0, tgt))
    while mem_banks[tgt] > 0:
        idx = iter_.pop(0)
        increaseblk(idx)
        mem_banks[tgt] -= 1
    cycles += 1
    if join_ints(mem_banks) in previous_states:
        break
    else:
        previous_states.append(join_ints(mem_banks))

# PART ONE
print(cycles)

# PART TWO
print(cycles - previous_states.index(join_ints(mem_banks)))