2022 - Day 7

2022/07/solution.ts

@@ -0,0 +1,191 @@
+const sample = await Deno.readTextFile("sample.txt");
+const input = await Deno.readTextFile("input.txt");
+
+/**** TYPES *********************************/
+
+interface LSCommandInfo {
+  type: "command";
+  command: "ls";
+}
+interface CDCommandInfo {
+  type: "command";
+  command: "cd";
+  name: string;
+}
+interface FileInfo {
+  type: "file";
+  size: number;
+  name: string;
+}
+interface DirectoryInfo {
+  type: "dir";
+  name: string;
+}
+type InfoItem = LSCommandInfo | CDCommandInfo | FileInfo | DirectoryInfo;
+
+class Directory {
+  public parent: Directory | undefined;
+  public name: string;
+  public size = 0;
+  public files: string[] = [];
+  public dirs: Directory[] = [];
+
+  constructor({ name, parent }: { name: string; parent?: Directory }) {
+    this.name = name;
+    this.parent = parent;
+  }
+
+  getDir(name: string): Directory | undefined {
+    return this.dirs.find((dir) => dir.name === name);
+  }
+
+  hasDir(name: string): boolean {
+    return this.dirs.some((dir) => dir.name === name);
+  }
+
+  hasFile(name: string): boolean {
+    return this.files.some((file) => file === name);
+  }
+
+  addDir(name: string): Directory {
+    if (this.hasDir(name)) {
+      return this.getDir(name)!;
+    }
+    const newDir = new Directory({ parent: this, name });
+    this.dirs.push(newDir);
+    return newDir;
+  }
+
+  get totalSize(): number {
+    return (
+      this.size + this.dirs.reduce((total, dir) => total + dir.totalSize, 0)
+    );
+  }
+}
+
+/**** FUNCTIONS *****************************/
+
+const parseData = (data: string): InfoItem[] => {
+  return data
+    .split("\n")
+    .filter(Boolean)
+    .map((line) => {
+      const parts = line.split(" ");
+      if (parts[0] === "$") {
+        return {
+          type: "command",
+          command: parts[1] === "ls" ? "ls" : "cd",
+          name: parts.slice(2).join(" "),
+        };
+      } else if (!isNaN(parseFloat(parts[0]))) {
+        return { type: "file", size: parseFloat(parts[0]), name: parts[1] };
+      } else {
+        return { type: "dir", name: parts.slice(1).join(" ") };
+      }
+    });
+};
+
+const flatten = (dir: Directory): Directory[] => [
+  dir,
+  ...dir.dirs.flatMap((dir) => flatten(dir)),
+];
+
+const printTree = (rootDir: Directory): void => {
+  const printDirecory = (level: number, dir: Directory) => {
+    console.log(
+      `${"".padStart(level, "  ")}${dir.name} - ${dir.size} - ${dir.totalSize}`
+    );
+    dir.dirs.forEach((dir) => printDirecory(level + 1, dir));
+  };
+
+  printDirecory(0, rootDir);
+};
+
+/**** PART 1 ********************************/
+
+const solvePart1 = (data: string): number => {
+  let rootDir: Directory | undefined = undefined;
+  let currentDir: Directory | undefined = undefined;
+
+  parseData(data).forEach((infoItem) => {
+    if (infoItem.type === "command" && infoItem.command === "cd") {
+      if (infoItem.name === "/") {
+        currentDir = rootDir = new Directory({ name: "/" });
+      } else if (infoItem.name === "..") {
+        if (!currentDir?.parent) {
+          throw new Error("There is no parent directory for " + infoItem.name);
+        }
+        currentDir = currentDir?.parent;
+      } else {
+        currentDir = currentDir?.addDir(infoItem.name);
+      }
+    } else if (infoItem.type === "file") {
+      if (!currentDir) {
+        throw new Error("There is no directory to add files to");
+      }
+      if (currentDir.hasFile(infoItem.name)) {
+        return;
+      }
+      currentDir.files.push(infoItem.name);
+      currentDir.size += infoItem.size;
+    } else if (infoItem.type === "dir") {
+      currentDir?.addDir(infoItem.name);
+    }
+  });
+  if (rootDir === undefined) {
+    return -1;
+  }
+  return flatten(rootDir)
+    .filter((dir) => dir.totalSize < 100000)
+    .map((dir) => dir.totalSize)
+    .reduce((sum, value) => sum + value, 0);
+};
+
+console.log("Sample:", solvePart1(sample)); // 95437
+console.log("Input", solvePart1(input)); //1611443
+
+/**** PART 2 ********************************/
+
+const solvePart2 = (data: string): number => {
+  let rootDir: Directory | undefined = undefined;
+  let currentDir: Directory | undefined = undefined;
+
+  parseData(data).forEach((infoItem) => {
+    if (infoItem.type === "command" && infoItem.command === "cd") {
+      if (infoItem.name === "/") {
+        currentDir = rootDir = new Directory({ name: "/" });
+      } else if (infoItem.name === "..") {
+        if (!currentDir?.parent) {
+          throw new Error("There is no parent directory for " + infoItem.name);
+        }
+        currentDir = currentDir?.parent;
+      } else {
+        currentDir = currentDir?.addDir(infoItem.name);
+      }
+    } else if (infoItem.type === "file") {
+      if (!currentDir) {
+        throw new Error("There is no directory to add files to");
+      }
+      if (currentDir.hasFile(infoItem.name)) {
+        return;
+      }
+      currentDir.files.push(infoItem.name);
+      currentDir.size += infoItem.size;
+    } else if (infoItem.type === "dir") {
+      currentDir?.addDir(infoItem.name);
+    }
+  });
+  if (rootDir === undefined) {
+    return -1;
+  }
+  return (
+    flatten(rootDir)
+      .filter((dir) => dir.totalSize >= 2080344)
+      .map((dir) => [dir.name, dir.totalSize] as [string, number])
+      .sort(([, a], [, b]) => a - b)
+      .shift()?.[1] || -1
+  );
+};
+
+console.log("Sample:", solvePart2(sample)); // 24933642
+console.log("Input", solvePart2(input)); //2086088