Solve 2018/04

2018/04/solve.py

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+import re
+import sys
+
+# PART 1
+
+ACTION_RE = r"\[(\d+)-(\d+)-(\d+) (\d+):(\d+)\] (.*)\n"
+GUARD_RE  = r"Guard #(\d+) begins shift"
+
+def load_actions(filename):
+	actions = []
+	with open(filename, "r") as f:
+		for line in f:
+			match = re.fullmatch(ACTION_RE, line)
+			y, m, d, hour, minute, action = match.groups()
+			y, m, d, hour, minute = int(y), int(m), int(d), int(hour), int(minute)
+			actions.append((y, m, d, hour, minute, action))
+	return actions
+
+def calculate_guards(actions):
+	guards = {}
+
+	guard = None
+	asleep_since = None
+
+	for action in sorted(actions):
+		_, _, _, _, m, text = action
+
+		match = re.fullmatch(GUARD_RE, text)
+		if match:
+			guard = int(match.group(1))
+
+		elif text == "falls asleep":
+			asleep_since = m
+
+		elif text == "wakes up":
+			l = guards.get(guard, [])
+			guards[guard] = l
+
+			l.append((asleep_since, m))
+
+	return guards
+
+def sleeps_longest(guards):
+	sleepiest_guard = None
+	sleepy_time = -1
+
+	for guard, sleep_times in guards.items():
+		total = 0
+		for start, end in sleep_times:
+			total += end - start
+
+		if total > sleepy_time:
+			sleepiest_guard = guard
+			sleepy_time = total
+
+	return sleepiest_guard
+
+def sleepiest_minute(times):
+	counter = {}
+	for start, end in times:
+		for m in range(start, end):
+			counter[m] = counter.get(m, 0) + 1
+
+	max_minute = None
+	amount = -1
+	for m, n in sorted(counter.items()):
+		if n > amount:
+			max_minute = m
+			amount = n
+
+	return max_minute
+
+# PART 2
+
+def sleep_times(times):
+	minutes = {}
+	for start, end in times:
+		for m in range(start, end):
+			minutes[m] = minutes.get(m, 0) + 1
+	return minutes
+
+def sleepy_minutes(guards):
+	minutes = {}
+	for guard, times in guards.items():
+		for m, n in sleep_times(times).items():
+			md = minutes.get(m, {})
+			minutes[m] = md
+			md[guard] = n
+
+	sleepy_minute = m
+	sleepy_guard = None
+	sleep_time = -1
+
+	for m, md in minutes.items():
+		for guard, n in md.items():
+			if n > sleep_time:
+				sleepy_minute = m
+				sleepy_guard = guard
+				sleep_time = n
+
+	return sleepy_guard, sleepy_minute
+
+def main(filename):
+	actions = load_actions(filename)
+	guards = calculate_guards(actions)
+	print(f"Solutions for {filename}")
+	guard = sleeps_longest(guards)
+	minute = sleepiest_minute(guards[guard])
+	print(f"Part 1: {guard * minute} - Guard {guard} slept most on minute {minute}.")
+	guard_2, minute_2 = sleepy_minutes(guards)
+	print(f"Part 2: {guard_2 * minute_2} - Guard {guard_2} slept most on minute {minute_2}.")
+
+if __name__ == "__main__":
+	for filename in sys.argv[1:]:
+		main(filename)

2018/04/test_input.txt

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+[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