u/nthistle's rolling window solution for Advent of Code 2022/6, and u/P1h3r1e3d13's variations

aoc-2022-6.nthistle.py

# https://www.reddit.com/r/adventofcode/comments/zdw0u6/2022_day_6_solutions/iz3mu21/
# https://topaz.github.io/paste/#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

with open("input.txt") as f:
    s = f.read().strip()

# alternate approach for part 2

cur_window = {}

# mjqjpqmgbljsphdztnvjfqwrcgsmlb
# XXXXXXXXXXXXXX
# to roll the window over one
#  XXXXXXXXXXXXXX (remove m, add d)

# first we need to populate cur_window with the first 14
for i in range(14):
    if s[i] not in cur_window:
        cur_window[s[i]] = 0
    cur_window[s[i]] += 1

# roll until cur_window has 14 unique elements
next_idx = 14
while len(cur_window.keys()) < 14:
    # roll the window by 1
    
    # adding next_idx
    if s[next_idx] not in cur_window:
        cur_window[s[next_idx]] = 0
    cur_window[s[next_idx]] += 1
    
    # delete next_idx - 14
    cur_window[s[next_idx - 14]] -= 1

    if cur_window[s[next_idx - 14]] == 0:
        del cur_window[s[next_idx - 14]]

    next_idx += 1

print(next_idx)

aoc-2022-6.p1h3r1e3d13-1.py

# Minimally adjust the original to use collections.Counter

from collections import Counter

with open("input.txt") as f:
    s = f.read().strip()

cur_window = Counter()

# mjqjpqmgbljsphdztnvjfqwrcgsmlb
# XXXXXXXXXXXXXX
# to roll the window over one
#  XXXXXXXXXXXXXX (remove m, add d)

# first we need to populate cur_window with the first 14
for i in range(14):
    #if s[i] not in cur_window:
    #    cur_window[s[i]] = 0
    cur_window[s[i]] += 1

# roll until cur_window has 14 unique elements
next_idx = 14
while len(cur_window.keys()) < 14:
    # roll the window by 1
    
    # adding next_idx
    #if s[next_idx] not in cur_window:
    #    cur_window[s[next_idx]] = 0
    cur_window[s[next_idx]] += 1
    
    # delete next_idx - 14
    cur_window[s[next_idx - 14]] -= 1

    if cur_window[s[next_idx - 14]] == 0:
        del cur_window[s[next_idx - 14]]
    #or cur_window = +cur_window

    next_idx += 1

print(next_idx)

aoc-2022-6.p1h3r1e3d13-2.py

# My version, with a little cleanup

from collections import Counter

win_size = 14

with open("input.txt") as f:
    s = f.read().strip()

cur_window = Counter()
# first we need to populate cur_window with the first 14
for i in range(win_size):
    cur_window[s[i]] += 1

# roll until cur_window has 14 unique elements
next_idx = win_size
while len(cur_window) < win_size:
    # roll the window by 1

    old_idx = next_idx - win_size
    
    # adding next_idx
    cur_window[s[next_idx]] += 1
    
    # delete old_idx
    cur_window[s[old_idx]] -= 1

    if cur_window[s[old_idx]] == 0:
        del cur_window[s[old_idx]]
    #or cur_window = +cur_window

    next_idx += 1

print(next_idx)