Initial Commit

2022/Day07CSharp/Program.cs

@@ -0,0 +1,205 @@
+// See https://aka.ms/new-console-template for more information
+using System.ComponentModel;
+using System.Drawing;
+using System.Xml;
+
+Console.WriteLine("Hello, World!");
+
+Directory exampleRoot = LoadData("example-input.txt");
+Directory puzzleRoot = LoadData("puzzle-input.txt");
+
+Console.WriteLine(String.Format("Part01: Example({0}), Puzzle({1})", Part01(exampleRoot, 100000), Part01(puzzleRoot, 100000)));
+
+Console.WriteLine(String.Format("Part02: Example({0}), Puzzle({1})" , Part02(exampleRoot, 70000000 - exampleRoot.Size, 30000000, exampleRoot.Size)
+                                                                    , Part02(puzzleRoot, 70000000 - puzzleRoot.Size, 30000000, puzzleRoot.Size)));
+
+int Part01(Directory root, int maxsize)
+{
+    int returnSize = 0;
+    int size = 0;
+
+    foreach (var file in root.Files)
+    {
+        size += file.Size;
+    }
+    foreach (var subdir in root.SubDirectories)
+    {
+        size += subdir.Size; 
+    }
+
+    if (size < maxsize) returnSize += size;
+
+    foreach (var subdir in root.SubDirectories)
+    {
+        returnSize += Part01(subdir, maxsize);
+    }
+
+    return returnSize;
+}
+
+int Part02(Directory root, int unusedSpace, int targetUnusedSpace, int returnSize)
+{
+    if (unusedSpace + root.Size > targetUnusedSpace)
+    {
+        returnSize = Int32.Min(returnSize, root.Size);
+    }
+    
+
+    foreach (var subdir in root.SubDirectories)
+    {
+        returnSize = Int32.Min(returnSize, Part02(subdir, unusedSpace, targetUnusedSpace, returnSize));
+    }
+
+    return returnSize;
+}
+
+Directory LoadData(string fileName)
+{
+    Directory root = new Directory("/", null);
+    Directory currentDir = root;
+
+    using (StreamReader reader = System.IO.File.OpenText(fileName))
+    {
+        while (!reader.EndOfStream)
+        {
+            string? line = reader.ReadLine();
+            if (line == null) throw new InvalidDataException();
+            if (line.Length == 0) continue;
+
+            // We should be reading commands here
+            if (line.StartsWith('$'))
+            {
+                var split = line.Split(' ');
+
+                if (split[1].StartsWith("cd"))
+                {
+                    if (split.Length != 3)
+                    {
+                        throw new InvalidDataException();
+                    }
+                    currentDir = HandleChangeDirectory(reader, split[2], currentDir);
+                } 
+                else if (split[1].StartsWith("ls"))
+                {
+                    currentDir = HandleListDirectory(reader, currentDir);
+                }
+            }
+            else
+            {
+                throw new InvalidDataException();
+            }
+        }
+
+    }
+
+    return root;
+}
+
+Directory HandleListDirectory(StreamReader reader, Directory currentDir)
+{
+    while (!reader.EndOfStream && reader.Peek() != '$')
+    {
+        string? line = reader.ReadLine();
+        if (line == null) throw new InvalidDataException();
+
+        var split = line.Split(" ");
+
+        int size = 0;
+
+        if (split[0].StartsWith("dir"))
+        {
+            if (currentDir.SubDirectories.Exists(x => x.Name.StartsWith(split[1])))
+            {
+                throw new InvalidDataException();
+            }
+            currentDir.SubDirectories.Add(new Directory(split[1], currentDir));
+        }
+        else if (Int32.TryParse(split[0], out size))
+        {
+            if (currentDir.Files.Exists(x => x.Name == split[1]))
+            {
+                throw new InvalidDataException();
+            }
+            currentDir.Files.Add(new File(split[1], size));
+        }
+        else
+        { throw new InvalidDataException(); }
+    }
+
+    return currentDir;
+}
+
+Directory HandleChangeDirectory(StreamReader reader, string argument, Directory currentDir)
+{
+    switch (argument)
+    {
+        case "/":
+            while (currentDir != null && !currentDir.Name.StartsWith("/")) 
+            {
+                if (currentDir.Parent == null) throw new InvalidDataException();
+                currentDir = currentDir.Parent;
+            }
+            return currentDir;
+
+        case "..":
+            if (currentDir.Parent == null)
+            {
+                throw new InvalidDataException();
+            }
+
+            currentDir = currentDir.Parent;
+            return currentDir;
+
+        default:
+            foreach (var subdir in currentDir.SubDirectories)
+            {
+                if (subdir.Name == argument)
+                {
+                    currentDir = subdir;
+                    return currentDir;
+                }
+            }
+            throw new InvalidDataException();
+    }
+}
+
+class File
+{
+    public string Name { get; set; }
+    public int Size { get; set; }
+
+    public File(string name, int size)
+    {
+        Name = name;
+        Size = size;
+    }
+}
+class Directory
+{
+    public List<Directory> SubDirectories { get; set; } = new List<Directory>();
+    public List<File> Files { get; set; } = new List<File>();
+    public Directory? Parent { get; set; } = null;
+
+    public string Name { get; set; }
+
+    public Directory(string name, Directory parent) { Name = name; Parent = parent; }
+
+    public int Size
+    {
+        get
+        {
+            int size = 0;
+
+            foreach (var subdir in SubDirectories)
+            {
+                size += subdir.Size;
+            }
+            foreach (var file in Files)
+            {
+                size += file.Size;
+            }
+
+            return size;
+        }
+    }
+}