Add solution for 2024 day 01

2024/day-01/common.rs

@@ -0,0 +1,35 @@
+use std::fs;
+use std::path::Path;
+
+
+#[derive(Debug)]
+pub struct PuzzleInputs {
+    pub left: Vec<i32>,
+    pub right: Vec<i32>,
+}
+
+impl PuzzleInputs {
+    pub fn parse<P>(path: P) -> Self
+        where P: AsRef<Path>
+    {
+        let mut left = Vec::new();
+        let mut right = Vec::new();
+
+        let content = fs::read_to_string(path).unwrap();
+
+        for line in content.lines() {
+            let mut parts = line.split(' ');
+
+            // unwrap is very festive
+            let first = parts.next().unwrap();
+            let first = first.parse().unwrap();
+            let last = parts.last().unwrap();
+            let last = last.parse().unwrap();
+
+            left.push(first);
+            right.push(last);
+        }
+
+        Self { left, right }
+    }
+}

2024/day-01/part_one.rs

@@ -0,0 +1,22 @@
+mod common;
+
+use common::PuzzleInputs;
+
+
+const INPUT_FILE: &str = "puzzle.txt";
+
+
+fn main() {
+    let mut inputs = PuzzleInputs::parse(INPUT_FILE);
+
+    inputs.left.sort();
+    inputs.right.sort();
+
+    let mut sum = 0;
+    for (l, r) in inputs.left.into_iter().zip(inputs.right) {
+        let dist = l.abs_diff(r);
+        sum += dist;
+    }
+
+    println!("{sum}");
+}

2024/day-01/part_two.rs

@@ -0,0 +1,30 @@
+mod common;
+
+use std::collections::HashMap;
+
+use common::PuzzleInputs;
+
+type Hist = HashMap<i32, i32>;
+
+
+const INPUT_FILE: &str = "puzzle.txt";
+
+
+fn main() {
+    let inputs = PuzzleInputs::parse(INPUT_FILE);
+    let mut hist = Hist::new();
+
+    for elem in inputs.right {
+        hist.entry(elem).and_modify(|e| *e += 1).or_insert(1);
+    }
+
+    let mut score = 0;
+
+    for elem in &inputs.left {
+        if let Some(x) = hist.get(elem) {
+            score += elem * x;
+        }
+    }
+
+    println!("{score:?}");
+}

2024/day-01/sample.txt

@@ -0,0 +1,6 @@
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3

flake.lock

@@ -0,0 +1,48 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1733024928,
+        "narHash": "sha256-n/DOfpKH1vkukuBnach91QBQId2dr5tkE7/7UrkV2zw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2c27ab2e60502d1ebb7cf38909de38663f762a79",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1733020719,
+        "narHash": "sha256-Chv9+3zrf1DhdB9JyskjoV0vJbCQEgkVqrU3p4RPLv8=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "8e18f10703112e6c33e1c0d8b93e8305f6f0a75c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,43 @@
+{
+    description = "Advent of Code";
+
+    inputs = {
+        nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+        rust-overlay = {
+            url = "github:oxalica/rust-overlay";
+            inputs.nixpkgs.follows = "nixpkgs";
+        };
+    };
+
+    outputs = { nixpkgs, rust-overlay, ... }:
+    let
+        lib = nixpkgs.lib;
+        systems = ["x86_64-linux"];
+
+        forEachSystem = fn: lib.genAttrs systems (system:
+        let
+            overlays = [ (import rust-overlay) ];
+            pkgs = import nixpkgs { inherit system overlays; };
+        in fn { inherit pkgs; } );
+
+        mkRustToolchain = pkgs: pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+    in {
+        devShells = forEachSystem ({ pkgs }: let
+            rustToolchain = mkRustToolchain pkgs;
+            rustNightlyToolchain = pkgs.rust-bin.selectLatestNightlyWith (t: t.minimal.override {
+                extensions = [ "rustfmt" ];
+            });
+
+        rustShell = pkgs.mkShell {
+                name = "AoC";
+
+                nativeBuildInputs = [
+                    rustToolchain
+                    rustNightlyToolchain
+                ];
+            };
+        in {
+            default = rustShell;
+        });
+    };
+}

rust-toolchain.toml

@@ -0,0 +1,5 @@
+[toolchain]
+channel = "stable"
+components = ["clippy", "rust-analyzer", "rust-src"]
+targets = ["x86_64-unknown-linux-gnu"]
+profile = "minimal" # includes rustc, cargo, and rust-std

rustfmt.toml

@@ -0,0 +1,18 @@
+edition = "2021"
+
+# Just enforce it here as well instead of relying on editorconfig alone
+hard_tabs = false
+tab_spaces = 4
+newline_style = "Unix"
+
+imports_granularity = "Module"
+group_imports = "StdExternalCrate"
+
+force_multiline_blocks = false
+fn_single_line = false
+comment_width = 100
+wrap_comments = true
+hex_literal_case = "Upper"
+blank_lines_upper_bound = 2
+overflow_delimited_expr = true
+reorder_impl_items = true