clean up day5, don't use itertools

2022-aoc/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-aoc-runner = "0.3.0"
-aoc-runner-derive = "0.3.0"
-itertools = "0.10.5"
-regex = "1.7.0"
+aoc-runner = "0.3"
+aoc-runner-derive = "0.3"
+#itertools = "0.10.5"
+regex = "1.7"

2022-aoc/src/d5.rs

@@ -1,44 +1,34 @@
 use aoc_runner_derive::{aoc as aoc_run, aoc_generator};
-use itertools::Itertools;
 
 type Stax = Vec<Vec<char>>;
 type Inst = (usize, usize, usize);
 
-enum Pstate {
-    Setup,
-    Instr,
-}
-
 #[aoc_generator(day5)]
 fn parse_input_day1(input: &str) -> (Stax, Vec<Inst>) {
     let mut out = Vec::new();
     let mut inst = Vec::new();
-    let mut state = Pstate::Setup;
+    let mut parsing_crates = true;
     for _ in 0..9 {
         out.push(Vec::new());
     }
 
     let re = regex::Regex::new(r"^move (\d+) from (\d+) to (\d+)$").unwrap();
     for line in input.lines() {
-        match state {
-            Pstate::Setup => {
+        if parsing_crates {
             if line.trim().starts_with('1') {
                 continue;
             }
             if line.trim().is_empty() {
-                    state = Pstate::Instr;
+                parsing_crates = false;
             }
-                for (i, cell) in line.chars().chunks(4).into_iter().enumerate() {
-                    let cell: String = cell.collect();
-                    let cell = cell.trim();
+            for (i, cell) in line.as_bytes().chunks(4).enumerate() {
+                let cell = std::str::from_utf8(cell).unwrap().trim();
                 if !cell.is_empty() {
                     let cell = cell.strip_prefix('[').unwrap().strip_suffix(']').unwrap();
                     out[i].push(cell.chars().next().unwrap());
                 }
             }
-            }
-            // parse the instructions
-            Pstate::Instr => {
+        } else {
             let ins = re.captures(line).unwrap();
             inst.push((
                 ins[1].parse().unwrap(),
@@ -47,7 +37,7 @@ fn parse_input_day1(input: &str) -> (Stax, Vec<Inst>) {
             ));
         }
     }
-    }
+
     for stack in out.iter_mut() {
         stack.reverse();
     }
@@ -85,9 +75,8 @@ fn p2((stax, inst): &(Stax, Vec<Inst>)) -> String {
             let c = from.pop().unwrap();
             tmp.push(c);
         }
-        for c in tmp.into_iter().rev() {
-            stax[*to].push(c);
-        }
+        tmp.reverse();
+        stax[*to].append(&mut tmp);
     }
     let mut s = String::with_capacity(9);
     for stack in stax {