113 lines
2.8 KiB
C#
113 lines
2.8 KiB
C#
|
var diskMap = File.ReadAllText("input.txt");
|
|||
|
|
var disk = GenerateFileSystem(diskMap); // I could create a class for this, but... meh
|
|||
|
|
var part1 = DefragBlocks(new List<int>(disk.Item1));
|
|||
|
|
var part2 = DefragFiles(new List<int>(disk.Item1), new List<(int Id, int Length, int Position)>(disk.Item2), disk.Item3);
|
|||
|
|
|
|||
|
|
Console.WriteLine($"Part1: {part1}\nPart2: {part2}");
|
|||
|
|
|
|||
|
|
long DefragFiles(List<int> fileSystem, List<(int Id, int Length, int Position)> files, List<(int Length, int Position)> free)
|
|||
|
|
{
|
|||
|
|
for (var i = files.Count - 1; i >= 0; i--)
|
|||
|
|
{
|
|||
|
|
var file = files[i];
|
|||
|
|
for (var j = 0; j < free.Count; j++)
|
|||
|
|
{
|
|||
|
|
var slot = free[j];
|
|||
|
|
if (file.Position < slot.Position)
|
|||
|
|
{
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
if (slot.Length >= file.Length)
|
|||
|
|
{
|
|||
|
|
for (var k = 0; k < file.Length; k++)
|
|||
|
|
{
|
|||
|
|
(fileSystem[slot.Position + k], fileSystem[file.Position + k]) = (fileSystem[file.Position + k], fileSystem[slot.Position + k]);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
free[j] = (slot.Length - file.Length, slot.Position + file.Length);
|
|||
|
|
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return CalculateChecksum(fileSystem);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
long DefragBlocks(List<int> fileSystem)
|
|||
|
|
{
|
|||
|
|
(int left, int right) = (0, fileSystem.Count - 1);
|
|||
|
|
while (left < right)
|
|||
|
|
{
|
|||
|
|
if (fileSystem[left] != -1)
|
|||
|
|
{
|
|||
|
|
left++;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
if (fileSystem[right] == -1)
|
|||
|
|
{
|
|||
|
|
right--;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
(fileSystem[left], fileSystem[right]) = (fileSystem[right], fileSystem[left]);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return CalculateChecksum(fileSystem);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
long CalculateChecksum(List<int> fileSystem)
|
|||
|
|
{
|
|||
|
|
var checksum = 0L;
|
|||
|
|
for (var i = 0; i < fileSystem.Count; i++)
|
|||
|
|
{
|
|||
|
|
var value = fileSystem[i];
|
|||
|
|
|
|||
|
|
if (value != -1)
|
|||
|
|
{
|
|||
|
|
checksum += value * i;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return checksum;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
(List<int>, List<(int Id, int Length, int Position)>, List<(int Length, int Position)>) GenerateFileSystem(string diskMapDescription)
|
|||
|
|
{
|
|||
|
|
|
|||
|
|
var file = true;
|
|||
|
|
var fileSystem = new List<int>();
|
|||
|
|
var freeSpace = new List<(int Length, int Position)>();
|
|||
|
|
var files = new List<(int Id, int Length, int Position)>();
|
|||
|
|
var id = 0;
|
|||
|
|
|
|||
|
|
foreach (var length in diskMapDescription.Select(c => int.Parse(c + "")))
|
|||
|
|
{
|
|||
|
|
var value = file ? id : -1;
|
|||
|
|
var position = fileSystem.Count;
|
|||
|
|
|
|||
|
|
if (file)
|
|||
|
|
{
|
|||
|
|
files.Add((id, length, position));
|
|||
|
|
id += 1;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
freeSpace.Add((length, position));
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
for (int i = 0; i < length; i++)
|
|||
|
|
{
|
|||
|
|
fileSystem.Add(value);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
file = !file;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return (fileSystem, files, freeSpace);
|
|||
|
|
}
|