advent-of-code-2022/2022/07/solution.ts

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