From d75c49e8c4ed4d8904a124ff06680bf7eb6da255 Mon Sep 17 00:00:00 2001
From: Xiretza <xiretza@xiretza.xyz>
Date: Mon, 5 Dec 2022 06:39:20 +0100
Subject: [PATCH] 2022 day5/rust: add solution

---
 2022/day5/rust/Cargo.toml  |  10 ++++
 2022/day5/rust/src/main.rs | 109 +++++++++++++++++++++++++++++++++++++
 Cargo.lock                 |  19 +++++++
 Cargo.toml                 |   1 +
 4 files changed, 139 insertions(+)
 create mode 100644 2022/day5/rust/Cargo.toml
 create mode 100644 2022/day5/rust/src/main.rs

diff --git a/2022/day5/rust/Cargo.toml b/2022/day5/rust/Cargo.toml
new file mode 100644
index 0000000..27430f5
--- /dev/null
+++ b/2022/day5/rust/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "rust_2022_05"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+aoc = { path = "../../../common/rust" }
+regex = "1.7.0"
diff --git a/2022/day5/rust/src/main.rs b/2022/day5/rust/src/main.rs
new file mode 100644
index 0000000..cf6a6cd
--- /dev/null
+++ b/2022/day5/rust/src/main.rs
@@ -0,0 +1,109 @@
+#![warn(clippy::pedantic)]
+
+use std::io::{stdin, Read};
+
+use regex::Regex;
+
+fn main() {
+    let mut data = String::new();
+    stdin().read_to_string(&mut data).unwrap();
+
+    let mut lines = data.lines();
+
+    let mut stacks = Vec::new();
+
+    for line in &mut lines {
+        if !line.contains('[') {
+            lines.next();
+            break;
+        }
+
+        for (i, crate_) in line.as_bytes().chunks(4).enumerate() {
+            if stacks.len() <= i {
+                stacks.push(vec![]);
+            }
+
+            if crate_.iter().all(|&c| c == b' ') {
+                // empty space
+                continue;
+            }
+
+            let crate_ = crate_.strip_suffix(b" ").unwrap_or(crate_);
+
+            let Some([crate_]) = crate_
+                .strip_prefix(b"[")
+                .and_then(|crate_| crate_.strip_suffix(b"]"))
+             else {
+                panic!("invalid crate {:?} {}", crate_, std::str::from_utf8(crate_).unwrap());
+            };
+
+            stacks[i].push(*crate_ as char);
+        }
+    }
+
+    for stack in &mut stacks {
+        stack.reverse();
+    }
+
+    let stacks = stacks;
+    let mut stacks_9000 = stacks.clone();
+    let mut stacks_9001 = stacks;
+
+    let regex = Regex::new(r"move (\d+) from (\d+) to (\d+)").unwrap();
+    for line in lines {
+        let matches = regex.captures(line).unwrap();
+
+        let amount: usize = matches[1].parse().unwrap();
+        let source: usize = matches[2].parse().unwrap();
+        let dest: usize = matches[3].parse().unwrap();
+
+        let source = source - 1;
+        let dest = dest - 1;
+
+        {
+            let (p1, p2) = stacks_9000.split_at_mut(usize::max(source, dest));
+
+            let (source, dest) = if source < dest {
+                (&mut p1[source], &mut p2[0])
+            } else {
+                (&mut p2[0], &mut p1[dest])
+            };
+
+            let sourceidx = source.len() - amount;
+
+            dest.extend(source[sourceidx..].iter().copied().rev());
+            source.truncate(sourceidx);
+        }
+
+        {
+            let (p1, p2) = stacks_9001.split_at_mut(usize::max(source, dest));
+
+            let (source, dest) = if source < dest {
+                (&mut p1[source], &mut p2[0])
+            } else {
+                (&mut p2[0], &mut p1[dest])
+            };
+
+            let sourceidx = source.len() - amount;
+
+            dest.extend(source[sourceidx..].iter().copied());
+            source.truncate(sourceidx);
+        }
+    }
+
+    println!(
+        "{}",
+        stacks_9000
+            .iter()
+            .map(|s| s.last().unwrap())
+            .collect::<String>()
+    );
+
+    println!(
+        "{}",
+        stacks_9001
+            .iter()
+            .map(|s| s.last().unwrap())
+            .collect::<String>()
+    );
+}
diff --git a/Cargo.lock b/Cargo.lock
index dc9d942..276ab35 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc936419f96fa211c1b9166887b38e5e40b19958e5b895be7c1f93adec7071ac"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "aoc"
 version = "0.1.0"
@@ -392,6 +401,8 @@ version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e076559ef8e241f2ae3479e36f97bd5741c0330689e217ad51ce2c76808b868a"
 dependencies = [
+ "aho-corasick",
+ "memchr",
  "regex-syntax",
 ]
 
@@ -484,6 +495,14 @@ dependencies = [
  "aoc",
 ]
 
+[[package]]
+name = "rust_2022_05"
+version = "0.1.0"
+dependencies = [
+ "aoc",
+ "regex",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.11"
diff --git a/Cargo.toml b/Cargo.toml
index 4daf70a..f0083d5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,4 +14,5 @@ members = [
 	"2022/day2/rust",
 	"2022/day3/rust",
 	"2022/day4/rust",
+	"2022/day5/rust",
 ]