// Some serious sub-optimal linq abuse going on here
protected override int GetAnswer(string input)
{
var events = ParseInput(input);
var orderedEvents = events.OrderBy(e => e.Month)
.ThenBy(e => e.Day)
.ThenBy(e => e.Hour)
.ThenBy(e => e.Minute)
.ToArray();
var guardInfos = new Dictionary <int, GuardInfo>();
var currentGuardId = 0;
for (var i = 0; i < orderedEvents.Length - 1; i++)
{
var evnt = orderedEvents[i];
switch (evnt.EventType)
{
case EventType.BeginShift:
currentGuardId = evnt.GuardId.Value;
if (!guardInfos.ContainsKey(currentGuardId))
{
guardInfos[currentGuardId] = new GuardInfo {
GuardId = currentGuardId
}
}
;
break;
case EventType.WakeUp:
// Nothing to do, only care about FallAsleep -> Wakeup Transitions
// Guards appear to always wake up before next guard shift
break;
case EventType.FallAsleep:
var wakeUpEvent = orderedEvents[i + 1];
if (wakeUpEvent.EventType != EventType.WakeUp)
{
throw new Exception("Your assumption that a wake up event always follows fall asleep is wrong.");
}
for (var m = evnt.Minute; m < wakeUpEvent.Minute; m++)
{
guardInfos[currentGuardId].MinuteSleepCounter[m]++;
guardInfos[currentGuardId].TotalMinutesSlept++;
}
break;
}
}
var max = guardInfos.Values.Select(gd => gd.TotalMinutesSlept).Max();
var gi = guardInfos.Values.First(gd => gd.TotalMinutesSlept == max);
return(gi.Answer);
}
public static Dictionary <int, GuardInfo> ParseGuards(List <Line> lines)
{
if (lines == null)
{
throw new ArgumentNullException(nameof(lines));
}
if (lines.Count == 0)
{
throw new ArgumentException("Value cannot be an empty collection.", nameof(lines));
}
var guards = new Dictionary <int, GuardInfo>();
GuardInfo currentGuard = null;
foreach (var line in lines)
{
if (line._kind == Line.Kind.BeginShift)
{
if (!guards.ContainsKey(line._guardId))
{
guards.Add(line._guardId,
new GuardInfo {
GuardId = line._guardId, Sleeps = new List <GuardInfo.SleepTime>()
});
}
currentGuard = guards[line._guardId];
}
else if (line._kind == Line.Kind.FallAsleep)
{
currentGuard.Sleeps.Add(new GuardInfo.SleepTime {
Start = line._timestamp.Minute
});
}
else if (line._kind == Line.Kind.WakeUp)
{
currentGuard.Sleeps.Last().End = line._timestamp.Minute;
}
}
return(guards);
}
public static (int Minute, int SleepCount) FindMinuteWithMaxSleep(this GuardInfo guard)
{
var sleepCountPerMinute = new int[60];
for (var i = 0; i < guard.Sleeps.Count; i++)
{
var s = guard.Sleeps[i];
for (var minute = s.Start; minute < s.End; minute++)
{
sleepCountPerMinute[minute]++;
}
}
var biggestIndex = 0;
for (var i = 0; i < 60; i++)
{
if (sleepCountPerMinute[i] > sleepCountPerMinute[biggestIndex])
{
biggestIndex = i;
}
}
return(biggestIndex, sleepCountPerMinute[biggestIndex]);
static void Main(string[] args)
{
//sort input by date and time
Regex logRegex = new Regex(@"\[1518-(\d\d)-(\d\d) (\d\d):(\d\d)\] (.*)");
MatchCollection logEntries = logRegex.Matches(System.IO.File.ReadAllText("input.txt"));
LogEntry[] entries = new LogEntry[logEntries.Count];
for (int i = 0; i < logEntries.Count; i++)
{
//parse to get relevant info
entries[i] = new LogEntry(int.Parse(logEntries[i].Groups[1].Value),
int.Parse(logEntries[i].Groups[2].Value),
int.Parse(logEntries[i].Groups[3].Value),
int.Parse(logEntries[i].Groups[4].Value),
logEntries[i].Groups[5].Value);
}
Array.Sort(entries);
//read the log
int guardID = 0, previousMinute = 0;
Dictionary <int, GuardInfo> guards = new Dictionary <int, GuardInfo>();
GuardInfo current, sleepiest = new GuardInfo
{
id = 0,
slept = 0,
map = new int[60]
};
//count minutes slept by each guard
//and create a minute map to identify the most sleepy minute later
foreach (LogEntry entry in entries)
{
if (entry.action.StartsWith('G')) //guard begins shift
{
guardID = int.Parse(entry.action.Replace("Guard #", "").Split(" ")[0]);
}
else if (entry.action.StartsWith('f')) //guard falls asleep
{
previousMinute = entry.minute;
}
else //guard wakes up
{
if (guards.ContainsKey(guardID))
{
current = guards[guardID];
}
else
{
current = new GuardInfo
{
id = guardID,
slept = 0,
map = new int[60]
};
guards.Add(guardID, current);
}
current.slept += (entry.minute - previousMinute);
for (int i = previousMinute; i < entry.minute; i++)
{
current.map[i]++;
}
guards[guardID] = current;
if (current.slept > sleepiest.slept)
{
sleepiest = current;
}
}
}
Console.WriteLine("Sleepiest guard is " + sleepiest.id);
int maxSleepCount = sleepiest.map.Max();
Console.WriteLine("Sleepiest minute is " + Array.IndexOf(sleepiest.map, maxSleepCount));
Console.WriteLine("First answer: " + sleepiest.id * Array.IndexOf(sleepiest.map, maxSleepCount));
//find absolute sleepiest minute and corresponding guard (second *)
foreach (GuardInfo g in guards.Values)
{
if (g.map.Max() > maxSleepCount)
{
sleepiest = g;
maxSleepCount = g.map.Max();
}
}
Console.WriteLine("Sleepiest guard is " + sleepiest.id);
Console.WriteLine("Sleepiest minute is " + Array.IndexOf(sleepiest.map, maxSleepCount));
Console.WriteLine("Second answer: " + sleepiest.id * Array.IndexOf(sleepiest.map, maxSleepCount));
Console.Read();
}
public static void Run(List <string> inputs)
{
GuardState lastState = GuardState.Off;
GuardInfo lastGuard = null;
int lastMinute = 0;
List <InputData> inputDatas = new List <InputData>();
List <GuardInfo> Guards = new List <GuardInfo>();
foreach (var input in inputs)
{
inputDatas.Add(new InputData(input));
}
foreach (var data in inputDatas.OrderBy(i => i.Time))
{
var currentMinute = data.Time.Minute;
if (data.Action == "Guard")
{
if (lastState == GuardState.Sleep) // if last guard was sleeping, finish his shift sleeping
{
lastGuard.Sleep(lastMinute, MinutesInHour);
}
lastGuard = Guards.FirstOrDefault(g => g.GuardNum == data.GuardNum);
if (lastGuard == null)
{
lastGuard = new GuardInfo(data.GuardNum);
Guards.Add(lastGuard);
}
lastState = GuardState.Off;
}
else if (data.Action == "wakes")
{
if (lastState == GuardState.Sleep)
{
lastGuard.Sleep(lastMinute, currentMinute);
}
lastState = GuardState.On;
}
else
{
lastState = GuardState.Sleep;
}
lastMinute = currentMinute;
}
//part 1
var lazyGuard =
Guards.Aggregate((guard1, guard2) => guard1.GetSleepTime() > guard2.GetSleepTime() ? guard1 : guard2);
var sleepTime = lazyGuard.GetHighestSleptHour();
var answer1 = lastGuard.GuardNum * sleepTime;
//part 2
var mostFrequentlySleepingGuard =
Guards.Aggregate(
(guard1, guard2) => guard1.GetMostSleptTime() > guard2.GetMostSleptTime() ? guard1 : guard2);
var answer2 = mostFrequentlySleepingGuard.GetHighestSleptHour() * mostFrequentlySleepingGuard.GuardNum;
}