Day 7

day7/Cargo.lock

@@ -0,0 +1,56 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "blanket"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b04ce3d2372d05d1ef4ea3fdf427da6ae3c17ca06d688a107b5344836276bc3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "day7"
+version = "0.1.0"
+dependencies = [
+ "blanket",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ea3d908b0e36316caf9e9e2c4625cdde190a7e6f440d794667ed17a1855e725"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.105"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60b9b43d45702de4c839cb9b51d9f529c5dd26a4aff255b42b1ebc03e88ee908"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ceab39d59e4c9499d4e5a8ee0e2735b891bb7308ac83dfb4e80cad195c9f6f3"

day7/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+blanket = "0.2"

day7/src/main.rs

@@ -1,3 +1,117 @@
-fn main() {
-    println!("Hello, world!");
+use std::{fs::read_to_string, iter::Peekable, str::Lines};
+
+#[derive(PartialEq, Debug)]
+struct File {
+    name: String,
+    size: usize,
+}
+
+impl File {
+    fn size(&self) -> usize {
+        self.size
+    }
+}
+
+#[derive(PartialEq, Debug)]
+struct Directory {
+    path: String,
+    files: Vec<File>,
+}
+
+fn size_of_dir(dirs: &[Directory], dir: &str) -> usize {
+    dirs.iter()
+        .filter_map(|d| {
+            if d.path.contains(dir) {
+                Some(d.files.iter().map(File::size).sum::<usize>())
+            } else {
+                None
+            }
+        })
+        .sum()
+}
+
+fn parse_command(
+    lines: &mut Peekable<Lines>,
+    cwd: &str,
+    directorys: &mut Vec<Directory>,
+) -> Result<String, String> {
+    let command = lines.next().unwrap().split_whitespace().collect::<Vec<_>>();
+    if command.len() < 2 || command[0] != "$" {
+        return Err("first line is not a command".to_owned());
+    }
+    match command[1] {
+        "cd" => {
+            if command.len() != 3 {
+                return Err("cd needs exactly 1 argument".to_owned());
+            }
+            match command[2] {
+                "/" => Ok("/".to_owned()),
+                ".." => {
+                    if cwd == "/" {
+                        Ok(cwd.to_owned())
+                    } else {
+                        let dirs = cwd.split_inclusive('/').collect::<Vec<_>>();
+                        let nwd = dirs[..(dirs.len() - 1)]
+                            .iter()
+                            .fold(String::new(), |s, v| s + v);
+                        Ok(nwd)
+                    }
+                }
+                dir => Ok(cwd.to_owned() + dir + "/"),
+            }
+        }
+        "ls" => {
+            while let Some(line) = lines.peek() {
+                if line.split_whitespace().collect::<Vec<_>>().first() == Some(&"$") {
+                    break;
+                }
+                let line = lines.next().unwrap();
+                let node = line.split_whitespace().collect::<Vec<_>>();
+                if node.len() != 2 {
+                    return Err("ls needs two inputs per line".to_owned());
+                }
+                match node[0] {
+                    "dir" => directorys.push(Directory {
+                        path: cwd.to_owned() + node[1] + "/",
+                        files: vec![],
+                    }),
+                    size => directorys
+                        .iter_mut()
+                        .find(|d| d.path == cwd)
+                        .unwrap()
+                        .files
+                        .push(File {
+                            name: node[1].to_owned(),
+                            size: size.parse().expect("invalid Size"),
+                        }),
+                }
+            }
+            Ok(cwd.to_owned())
+        }
+        _ => Err("unknown command".to_owned()),
+    }
+}
+
+fn main() {
+    const TOTAL_SPACE: usize = 70000000;
+    const NEEDED_FREE: usize = 30000000;
+    let input = read_to_string("input.txt").unwrap();
+    let mut lines = input.lines().peekable();
+    let mut dirs = vec![Directory {
+        path: "/".to_owned(),
+        files: vec![],
+    }];
+    let mut cwd = "/".to_owned();
+    while lines.peek().is_some() {
+        cwd = parse_command(&mut lines, &cwd, &mut dirs).expect("invalid input");
+    }
+    let sizes = dirs.iter().map(|d| size_of_dir(&dirs, &d.path));
+    let sol1: usize = sizes.clone().filter(|s| s < &100_000).sum();
+    println!("{sol1}");
+    let used = size_of_dir(&dirs, "/");
+    let free = TOTAL_SPACE - used;
+    let additional = NEEDED_FREE - free;
+    println!("{used} Bytes used, {free} Bytes free, {additional} Bytes need to be freed");
+    let sol2 = sizes.filter(|s| s >= &additional).min().unwrap();
+    println!("Deleting Directory with size {sol2}");
 }