done with day 7

2022-aoc/Cargo.toml

@@ -8,5 +8,6 @@ edition = "2021"
 [dependencies]
 aoc-runner = "0.3"
 aoc-runner-derive = "0.3"
+lazy_static = "1.4.0"
 #itertools = "0.10.5"
 regex = "1.7"

2022-aoc/src/d7.rs

@@ -0,0 +1,127 @@
+use aoc_runner_derive::{aoc as aoc_run, aoc_generator};
+use lazy_static::lazy_static;
+use regex::Regex;
+use std::collections::{HashMap, HashSet};
+
+type Files = HashMap<String, u32>;
+type Dirs = HashMap<String, Node>;
+
+#[derive(Default, Debug)]
+struct Node {
+    files: HashSet<String>,
+    dirs: HashSet<String>,
+}
+
+enum Parsing {
+    Command,
+    Listing,
+}
+
+fn command(c: &str, cwd: &mut Vec<String>) -> Parsing {
+    if c.starts_with("$ cd") {
+        let dest = String::from_utf8(c.as_bytes()[5..].to_vec()).unwrap();
+        if dest == ".." {
+            let _ = cwd.pop();
+        } else {
+            cwd.push(dest);
+        }
+        return Parsing::Command;
+    }
+    Parsing::Listing
+}
+
+fn listing(c: &str, cwd: &[String], files: &mut Files, node: &mut Node) {
+    lazy_static! {
+        static ref FILE: Regex = Regex::new(r"^(\d+) ([a-z.]+$)").unwrap();
+        static ref DIR: Regex = Regex::new(r"^dir ([a-z.]+$)").unwrap();
+    }
+    let mut path = cwd.to_vec();
+    if let Some(cap) = FILE.captures(c) {
+        let sz = cap[1].parse().unwrap();
+        let name = cap[2].to_owned();
+        path.push(name);
+        let name = path.join("/");
+        files.insert(name.clone(), sz);
+        node.files.insert(name);
+    } else if let Some(cap) = DIR.captures(c) {
+        let name = cap[1].to_owned();
+        path.push(name);
+        let name = path.join("/");
+        node.dirs.insert(name);
+    } else {
+        dbg!("what the fuck", c);
+    }
+}
+
+#[aoc_generator(day7)]
+fn parse_input_day1(input: &str) -> (Dirs, Files) {
+    let mut dirs = Dirs::new();
+    let mut files = Files::new();
+    let mut cwd = Vec::new();
+    let mut pstatus = Parsing::Command;
+    let mut node = Node::default();
+    for line in input.lines() {
+        match pstatus {
+            Parsing::Command => {
+                if line.starts_with('$') {
+                    pstatus = command(line, &mut cwd);
+                } else {
+                    pstatus = Parsing::Listing;
+                    listing(line, &cwd, &mut files, &mut node);
+                }
+            }
+            Parsing::Listing => {
+                if line.starts_with('$') {
+                    // we are just finished with a listing, so add the node to the map
+                    dirs.insert(cwd.join("/"), node);
+                    node = Node::default();
+                    pstatus = command(line, &mut cwd);
+                } else {
+                    listing(line, &cwd, &mut files, &mut node);
+                }
+            }
+        }
+    }
+    dirs.insert(cwd.join("/"), node);
+    (dirs, files)
+}
+
+#[aoc_run(day7, part1)]
+fn part1((dirs, files): &(Dirs, Files)) -> u32 {
+    let mut sizes = Vec::new();
+    for (name, _node) in dirs.iter() {
+        sizes.push((name, size(name, dirs, files)));
+    }
+    sizes
+        .into_iter()
+        .filter_map(|e| if e.1 <= 100000 { Some(e.1) } else { None })
+        .sum()
+}
+
+#[aoc_run(day7, part2)]
+fn part2((dirs, files): &(Dirs, Files)) -> u32 {
+    let mut sizes = Vec::new();
+    for (name, _node) in dirs.iter() {
+        sizes.push((name, size(name, dirs, files)));
+    }
+    let total = size("/", dirs, files);
+    let avail = 70_000_000 - total;
+    let needed = 30_000_000 - avail;
+
+    sizes.sort_by(|a, b| (a.1).cmp(&b.1));
+    sizes.iter().find(|x| x.1 >= needed).unwrap().1
+}
+
+fn size(name: &str, dirs: &Dirs, files: &Files) -> u32 {
+    let mut out = 0;
+    if let Some(node) = dirs.get(name) {
+        for file in node.files.iter() {
+            out += files.get(file).unwrap();
+        }
+        for dir in node.dirs.iter() {
+            out += size(dir, dirs, files);
+        }
+    }
+
+    out
+}

2022-aoc/src/lib.rs

@@ -6,5 +6,6 @@ mod d3;
 mod d4;
 mod d5;
 mod d6;
+mod d7;
 
 aoc_lib! { year = 2022 }