day07 part 1

day07/src/main/java/com/felixalb/app/App.java

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+package com.felixalb.app;
+
+import java.io.*;
+import java.util.*;
+import java.nio.file.*;
+
+
+public class App {
+  private static String[] readLines(String filename) {
+    try {
+      return Files.readAllLines(Paths.get(filename)).toArray(new String[0]);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  public static void main(String[] args) {
+    if (args.length < 1) {
+      System.out.println("Usage: java App <filename>");
+      return;
+    }
+
+    String filename = args[0];
+    String[] lines = readLines(filename);
+
+    System.out.println("Lines: " + lines.length);
+
+    FileSystemReader fileSystemReader = new FileSystemReader(lines);
+
+
+    // Part 1
+    FileNode p1_root = fileSystemReader.getRoot();
+    Integer directorySizeSum = 0;
+    ArrayList<Integer> p1_sizes = p1_root.getDirectorySizesFlat(new ArrayList<Integer>());
+    // System.out.println("Part 1: " + p1_sizes);
+    for (Integer size : p1_sizes) {
+      if (size <= 100000) {
+        directorySizeSum += size;
+      }
+    }
+    p1_root.printNode("");
+    System.out.println("Part 1: " + directorySizeSum);
+
+
+  }
+}

day07/src/main/java/com/felixalb/app/FileNode.java

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+package com.felixalb.app;
+
+import java.util.ArrayList;
+
+class FileNode {
+  private String name;
+  private Integer size;
+  private Boolean isDirectory;
+  private ArrayList<FileNode> children = new ArrayList<FileNode>();
+
+  public FileNode(String name, Boolean isDirectory) {
+    this.name = name;
+    this.children = new ArrayList<FileNode>();
+    this.isDirectory = isDirectory;
+  }
+
+  public Integer getSize() {
+    if (this.isDirectory) {
+      Integer size = 0;
+      for (FileNode child : this.children) {
+        size += child.getSize();
+      }
+      return size;
+    } else {
+      return this.size;
+    }
+  }
+
+  public void setSize(Integer size) {
+    if (this.isDirectory) {
+      throw new RuntimeException("Cannot set size of directory");
+    }
+    this.size = size;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public ArrayList<FileNode> getChildren() {
+    if (!this.isDirectory) {
+      throw new RuntimeException("Cannot get children of file");
+    }
+    return this.children;
+  }
+
+  public void appendChild(FileNode child) {
+    this.children.add(child);
+  }
+
+  public void printNode(String prefix) {
+    System.out.println(prefix + this.name + " (" + this.getSize() + ")");
+    if (this.isDirectory) {
+      for (FileNode child : this.children) {
+        child.printNode(prefix + "|  ");
+      }
+    }
+  }
+
+  public ArrayList<Integer> getDirectorySizesFlat(ArrayList<Integer> sizes) {
+    if (!this.isDirectory) {
+      return sizes;
+    }
+    sizes.add(this.getSize());
+    for (FileNode child : this.children) {
+      child.getDirectorySizesFlat(sizes);
+    }
+    return sizes;
+  }
+}

day07/src/main/java/com/felixalb/app/FileSystemReader.java

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+package com.felixalb.app;
+
+import java.util.ArrayList;
+
+public class FileSystemReader {
+  ArrayList<String[]> commands = new ArrayList<String[]>();
+  ArrayList<String> workingDirectory = new ArrayList<String>();
+  FileNode root = new FileNode("/", true);
+
+  public FileSystemReader(String[] lines) {
+    ArrayList<String> currentCommand = new ArrayList<String>();
+    for (String line : lines) {
+      if (line.startsWith("$") && currentCommand.size() > 0) {
+        commands.add(currentCommand.toArray(new String[0]));
+        currentCommand = new ArrayList<String>();
+      }
+
+      currentCommand.add(line);
+    }
+    if (currentCommand.size() > 0) {
+      commands.add(currentCommand.toArray(new String[0]));
+    }
+
+    System.out.println("Commands: " + commands.size());
+
+    for (String[] command : commands) {
+      this.parseCommand(command);
+    }
+  }
+
+  public void printState() {
+    System.out.println("Working directory: " + this.workingDirectory);
+    this.root.printNode("");
+  }
+
+  public FileNode getRoot() {
+    return this.root;
+  }
+
+  private FileNode getNode(String path, Boolean create) {
+    String[] pathParts = path.split("/");
+    FileNode currentNode = root;
+    for (String pathPart : pathParts) {
+      if (pathPart.length() == 0) {
+        continue;
+      }
+      ArrayList<FileNode> children = currentNode.getChildren();
+      FileNode child = null;
+      for (FileNode childCandidate : children) {
+        if (childCandidate.getName().equals(pathPart)) {
+          child = childCandidate;
+          break;
+        }
+      }
+
+      if (child == null) {
+        if (create) {
+          child = new FileNode(pathPart, false);
+          currentNode.appendChild(child);
+        } else {
+          return null;
+        }
+      }
+      currentNode = child;
+    }
+    return currentNode;
+  }
+
+  public ArrayList<String[]> getCommands() {
+    return commands;
+  }
+
+  public void parseCommand(String[] command) {
+    String[] commandParts = command[0].split(" ");
+    String commandName = commandParts[1];
+    // System.out.println("Command: " + commandName);
+
+    if (commandName.equals("cd")) {
+      String path = commandParts[2];
+      switch (path) {
+        case "/" :
+          workingDirectory = new ArrayList<String>();
+          break;
+        case ".." :
+          workingDirectory.remove(workingDirectory.size() - 1);
+          break;
+        default :
+          workingDirectory.add(path);
+          break;
+      }
+      // System.out.println("Working directory: /" + String.join("/", workingDirectory));
+    } else if (commandName.equals("ls")) {
+      FileNode dir = getNode(String.join("/", workingDirectory), false);
+      if (dir == null) {
+        System.out.println("ls: cannot access " + String.join("/", workingDirectory) + ": No such file or directory");
+      } else {
+        for (String line : command) {
+          String[] lineParts = line.split(" ");
+          if (lineParts[0].equals("$")) {
+            continue;
+          }
+          if (lineParts[0].equals("dir")) {
+            FileNode newDir = new FileNode(lineParts[1], true);
+            dir.appendChild(newDir);
+          } else {
+            FileNode newFile = new FileNode(lineParts[1], false);
+            newFile.setSize(Integer.parseInt(lineParts[0]));
+            dir.appendChild(newFile);
+          }
+        }
+      }
+    } else {
+      throw new RuntimeException("Unknown command: '" + commandName + "'");
+    }
+  }
+}

day07/src/test/java/com/felixalb/app/AppTest.java

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+package com.felixalb.app;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+/**
+ * Unit test for simple App.
+ */
+public class AppTest 
+{
+    /**
+     * Rigorous Test :-)
+     */
+    @Test
+    public void shouldAnswerWithTrue()
+    {
+        assertTrue( true );
+    }
+}