day07 finished

src/days/day07/mod.rs

@@ -0,0 +1,341 @@
+use std::{
+    cell::{Cell, RefCell},
+    num::ParseIntError,
+    rc::{Rc, Weak},
+};
+
+use super::template::{DayTrait, ResultType};
+use thiserror::Error;
+
+const DAY_NUMBER: usize = 7;
+
+pub struct Day;
+
+impl DayTrait for Day {
+    fn get_day_number(&self) -> usize {
+        DAY_NUMBER
+    }
+
+    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+        let root = Directory::parse(lines)?;
+        let result = root
+            .iter()
+            .filter_map(|dir| {
+                let size = dir.size();
+                if size <= 100000 {
+                    Some(size)
+                } else {
+                    None
+                }
+            })
+            .sum();
+        Ok(ResultType::Integer(result))
+    }
+
+    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+        const AVAIL: i64 = 70_000_000;
+        const REQUIRED: i64 = 30_000_000;
+        let root = Directory::parse(lines)?;
+        let to_free = REQUIRED - (AVAIL - root.size());
+        let result = root
+            .iter()
+            .filter_map(|dir| {
+                let size = dir.size();
+                if size >= to_free {
+                    Some(size)
+                } else {
+                    None
+                }
+            })
+            .min()
+            .unwrap_or(0);
+        Ok(ResultType::Integer(result))
+    }
+}
+
+#[derive(Debug, Error)]
+enum DirectoryError {
+    #[error("Directory does not exist: {0}")]
+    NoSuchDirectory(String),
+
+    #[error("Directory has no parent")]
+    NoParentDirectory,
+
+    #[error("Illegal command: {0}")]
+    IllegalCommand(String),
+
+    #[error("No a legal Number")]
+    IllegalNumber(#[from] ParseIntError),
+}
+
+#[derive(Debug)]
+struct Node {
+    parent: Option<Weak<RefCell<Node>>>,
+    name: String,
+    sub_dirs: Vec<Rc<RefCell<Node>>>,
+    file_size: i64,
+    size: Cell<Option<i64>>,
+}
+
+impl Node {
+    fn root() -> Node {
+        Node {
+            parent: None,
+            name: "/".to_owned(),
+            sub_dirs: vec![],
+            file_size: 0,
+            size: Cell::new(None),
+        }
+    }
+
+    fn add_subdir(&mut self, subdir: Rc<RefCell<Node>>) {
+        self.sub_dirs.push(subdir);
+    }
+
+    fn add_file(&mut self, _name: &str, size: i64) {
+        self.file_size += size;
+    }
+
+    fn size(&self) -> i64 {
+        self.size.get().unwrap_or_else(|| {
+            let subsize: i64 = self.sub_dirs.iter().map(|sub| sub.borrow().size()).sum();
+            let size = subsize + self.file_size;
+
+            self.size.set(Some(size));
+            size
+        })
+    }
+}
+
+#[derive(Debug, Clone)]
+struct Directory {
+    node: Rc<RefCell<Node>>,
+}
+
+impl Directory {
+    pub fn root() -> Directory {
+        Directory {
+            node: Rc::new(RefCell::new(Node::root())),
+        }
+    }
+
+    fn create(node: Rc<RefCell<Node>>) -> Directory {
+        Directory { node }
+    }
+
+    #[allow(dead_code)]
+    pub fn name(&self) -> String {
+        self.node.borrow().name.to_string()
+    }
+
+    pub fn size(&self) -> i64 {
+        self.node.borrow().size()
+    }
+
+    #[allow(dead_code)]
+    pub fn file_size(&self) -> i64 {
+        self.node.borrow().file_size
+    }
+
+    pub fn add_subdir(&mut self, name: &str) {
+        let subdir = Rc::new(RefCell::new(Node {
+            parent: Some(Rc::downgrade(&self.node)),
+            name: name.to_owned(),
+            sub_dirs: vec![],
+            file_size: 0,
+            size: Cell::new(None),
+        }));
+        self.node.borrow_mut().add_subdir(subdir);
+    }
+
+    pub fn add_file(&mut self, name: &str, size: i64) {
+        self.node.borrow_mut().add_file(name, size)
+    }
+
+    pub fn parent(&self) -> Option<Directory> {
+        self.node
+            .borrow()
+            .parent
+            .as_ref()
+            .and_then(|node| node.upgrade())
+            .map(|node| Directory { node })
+    }
+
+    pub fn get_subdir(&self, name: &str) -> Option<Directory> {
+        let node = self.node.borrow();
+        let sub_node = node.sub_dirs.iter().find(|node| node.borrow().name == name);
+        sub_node.map(|node| Directory::create(node.clone()))
+    }
+
+    pub fn parse(lines: &[String]) -> Result<Directory, DirectoryError> {
+        let root = Directory::root();
+        let mut current = root.clone();
+        for line in lines {
+            match line.split_whitespace().collect::<Vec<&str>>()[..] {
+                ["$", "cd", dir] => {
+                    current = match dir {
+                        "/" => root.clone(),
+                        ".." => {
+                            let Some(next) = current.parent() else {
+                            return Err(DirectoryError::NoParentDirectory);
+                        };
+                            next
+                        }
+                        _ => {
+                            let Some(next) = current.get_subdir(dir) else {
+                            return Err(DirectoryError::NoSuchDirectory(dir.to_owned()))
+                        };
+                            next
+                        }
+                    };
+                }
+                ["$", "ls"] => {} // Command can safely be ignored
+                ["dir", name] => {
+                    current.add_subdir(name);
+                }
+                [size, name] => {
+                    let size = size.parse::<i64>()?;
+                    current.add_file(name, size);
+                }
+                _ => return Err(DirectoryError::IllegalCommand(line.to_owned())),
+            }
+        }
+        Ok(root)
+    }
+
+    pub fn iter(&self) -> DirectoryIterator {
+        DirectoryIterator::create(self.node.clone())
+    }
+}
+
+#[derive(Debug)]
+struct DirectoryIterator {
+    directory: Rc<RefCell<Node>>,
+    subdirectory: Option<(usize, Box<DirectoryIterator>)>,
+    finished: bool,
+}
+
+impl DirectoryIterator {
+    pub fn create(directory: Rc<RefCell<Node>>) -> DirectoryIterator {
+        DirectoryIterator {
+            directory,
+            subdirectory: None,
+            finished: false,
+        }
+    }
+}
+
+impl Iterator for DirectoryIterator {
+    type Item = Directory;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.finished {
+            return None;
+        }
+        if let Some((subdirectory, sub_iterator)) = self.subdirectory.as_mut() {
+            if let Some(next) = sub_iterator.next() {
+                Some(next)
+            } else {
+                let dir = self.directory.borrow();
+                let subdirectory = *subdirectory + 1;
+                if subdirectory < dir.sub_dirs.len() {
+                    let subdir = dir.sub_dirs[subdirectory].clone();
+                    let mut sub_iterator = DirectoryIterator::create(subdir);
+                    let result = sub_iterator.next();
+                    self.subdirectory = Some((subdirectory, Box::new(sub_iterator)));
+                    result
+                } else {
+                    self.finished = true;
+                    None
+                }
+            }
+        } else {
+            let dir = self.directory.borrow();
+            if !dir.sub_dirs.is_empty() {
+                let subdir = dir.sub_dirs[0].clone();
+                let sub_iterator = DirectoryIterator::create(subdir);
+                self.subdirectory = Some((0, Box::new(sub_iterator)));
+            } else {
+                self.finished = true;
+            }
+
+            Some(Directory {
+                node: self.directory.clone(),
+            })
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::common::file::read_lines;
+    use anyhow::Result;
+
+    #[test]
+    fn test_create_directory() {
+        let directory = Directory::root();
+        assert_eq!(directory.name(), "/");
+        assert_eq!(directory.size(), 0);
+    }
+
+    #[test]
+    fn test_create_and_get_subdir() {
+        let mut root = Directory::root();
+        root.add_file("file1", 100);
+        root.add_file("file2", 200);
+        root.add_subdir("subdir");
+        let mut subdir = root.get_subdir("subdir").unwrap();
+        subdir.add_file("file3", 300);
+        subdir.add_file("file4", 400);
+
+        assert_eq!(subdir.name(), "subdir");
+        assert_eq!(subdir.size(), 700);
+        assert_eq!(root.size(), 1000);
+        assert_eq!(root.file_size(), 300);
+    }
+
+    #[test]
+    fn test_total_size() -> Result<()> {
+        let day = Day {};
+        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let dir = Directory::parse(&lines)?;
+        assert_eq!(dir.size(), 48381165);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_iterator() -> Result<()> {
+        let day = Day {};
+        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let expected = vec!["/", "a", "e", "d"];
+        let dir = Directory::parse(&lines)?;
+        let result: Vec<_> = dir.iter().map(|dir| dir.name()).collect();
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_part1() -> Result<()> {
+        let day = Day {};
+        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::Integer(95437);
+        let result = day.part1(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_part2() -> Result<()> {
+        let day = Day {};
+        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::Integer(24933642);
+        let result = day.part2(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+}