[WIP] Solution to problem 4 part 1 in Python

src/Year_2018/P4.py

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+# --- Day 4: Repose Record ---
+
+# You've sneaked into another supply closet - this time, it's across from the
+# prototype suit manufacturing lab. You need to sneak inside and fix the issues
+# with the suit, but there's a guard stationed outside the lab, so this is as
+# close as you can safely get.
+
+# As you search the closet for anything that might help, you discover that
+# you're not the first person to want to sneak in. Covering the walls, someone
+# has spent an hour starting every midnight for the past few months secretly
+# observing this guard post! They've been writing down the ID of the one guard
+# on duty that night - the Elves seem to have decided that one guard was enough
+# for the overnight shift - as well as when they fall asleep or wake up while
+# at their post (your puzzle input).
+
+# For example, consider the following records, which have already been
+# organized into chronological order:
+
+# [1518-11-01 00:00] Guard #10 begins shift
+# [1518-11-01 00:05] falls asleep
+# [1518-11-01 00:25] wakes up
+# [1518-11-01 00:30] falls asleep
+# [1518-11-01 00:55] wakes up
+# [1518-11-01 23:58] Guard #99 begins shift
+# [1518-11-02 00:40] falls asleep
+# [1518-11-02 00:50] wakes up
+# [1518-11-03 00:05] Guard #10 begins shift
+# [1518-11-03 00:24] falls asleep
+# [1518-11-03 00:29] wakes up
+# [1518-11-04 00:02] Guard #99 begins shift
+# [1518-11-04 00:36] falls asleep
+# [1518-11-04 00:46] wakes up
+# [1518-11-05 00:03] Guard #99 begins shift
+# [1518-11-05 00:45] falls asleep
+# [1518-11-05 00:55] wakes up
+
+# Timestamps are written using year-month-day hour:minute format. The guard
+# falling asleep or waking up is always the one whose shift most recently
+# started. Because all asleep/awake times are during the midnight hour
+# (00:00 - 00:59), only the minute portion (00 - 59) is relevant for those
+# events.
+
+# Visually, these records show that the guards are asleep at these times:
+
+# Date   ID   Minute
+#             000000000011111111112222222222333333333344444444445555555555
+#             012345678901234567890123456789012345678901234567890123456789
+# 11-01  #10  .....####################.....#########################.....
+# 11-02  #99  ........................................##########..........
+# 11-03  #10  ........................#####...............................
+# 11-04  #99  ....................................##########..............
+# 11-05  #99  .............................................##########.....
+
+# The columns are Date, which shows the month-day portion of the relevant day;
+# ID, which shows the guard on duty that day; and Minute, which shows the
+# minutes during which the guard was asleep within the midnight hour. (The
+# Minute column's header shows the minute's ten's digit in the first row and
+# the one's digit in the second row.) Awake is shown as ., and asleep is shown
+# as #.
+
+# Note that guards count as asleep on the minute they fall asleep, and they
+# count as awake on the minute they wake up. For example, because Guard #10
+# wakes up at 00:25 on 1518-11-01, minute 25 is marked as awake.
+
+# If you can figure out the guard most likely to be asleep at a specific time,
+# you might be able to trick that guard into working tonight so you can have
+# the best chance of sneaking in. You have two strategies for choosing the best
+# guard/minute combination.
+
+# Strategy 1: Find the guard that has the most minutes asleep. What minute does
+# that guard spend asleep the most?
+
+# In the example above, Guard #10 spent the most minutes asleep, a total of 50
+# minutes (20+25+5), while Guard #99 only slept for a total of 30 minutes
+# (10+10+10). Guard #10 was asleep most during minute 24 (on two days, whereas
+# any other minute the guard was asleep was only seen on one day).
+
+# While this example listed the entries in chronological order, your entries
+# are in the order you found them. You'll need to organize them before they can
+# be analyzed.
+
+# What is the ID of the guard you chose multiplied by the minute you chose? (In
+# the above example, the answer would be 10 * 24 = 240.)
+
+import re
+from collections import Counter, defaultdict
+
+with open("files/P4.txt") as f:
+    schedule = [line for line in f.read().strip().split("\n")]
+
+sorted_schedule = sorted(schedule)
+
+
+def part_1() -> None:
+    schedule_dict = defaultdict(list)
+    for line in sorted_schedule:
+        split_str = re.split(r"] | #| |\[", line)
+        if "Guard" in split_str:
+            _, date, time, _, guard_no, *_ = split_str
+        elif "falls" in split_str:
+            _, date, time, *_ = split_str
+            starting_time = int(time[-2:])
+        elif "wakes" in split_str:
+            _, date, time, *_ = split_str
+            ending_time = int(time[-2:])
+            for i in range(starting_time, ending_time):
+                schedule_dict[date, guard_no].append(i)
+
+    list_dict = defaultdict(list)
+    for k, v in schedule_dict.items():
+        for val in v:
+            list_dict[k[1]].append(val)
+
+    max_dict = defaultdict(list)
+    longest_dict = defaultdict(int)
+    for k, v in list_dict.items():
+        max_dict[k].append(Counter(v).most_common()[0])
+        longest_dict[k] += len(v)
+
+    max_key = max(longest_dict, key=longest_dict.get)
+    max_min = int(max_dict[max_key][0][0])
+
+    print(int(max_key) * max_min)
+
+
+if __name__ == "__main__":
+    part_1()