From fc0f216511306c28863b9905503422776889183e Mon Sep 17 00:00:00 2001
From: kageru <kageru@encode.moe>
Date: Thu, 22 Dec 2022 21:03:12 +0100
Subject: [PATCH] Make 2022/22/1 work

---
 2022/src/bin/day22.rs | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/2022/src/bin/day22.rs b/2022/src/bin/day22.rs
index c648b6c..006cb77 100644
--- a/2022/src/bin/day22.rs
+++ b/2022/src/bin/day22.rs
@@ -5,8 +5,9 @@ use std::fmt;
 use aoc2022::{
     boilerplate,
     common::*,
-    grid::{draw_ascii, Direction, Grid, HashGrid, PositionND},
+    grid::{Direction, Grid, HashGrid, PositionND},
 };
+use itertools::Itertools;
 
 const DAY: usize = 22;
 type Parsed = (HashGrid<Field, 2>, Vec<(i64, Turn)>);
@@ -15,7 +16,6 @@ type Parsed = (HashGrid<Field, 2>, Vec<(i64, Turn)>);
 enum Field {
     Empty = b'.' as isize,
     Wall = b'#' as isize,
-    Me = b'O' as isize, // for debug printing the grid
     #[default]
     Missing = b' ' as isize,
 }
@@ -52,16 +52,21 @@ fn parse_input(raw: &str) -> Parsed {
     let moves = moves
         .split_inclusive(['L', 'R'])
         .map(|s| s.split_at(s.len() - 1))
-        .map(|(n, d)| if n == "" { (parse_num(d), Turn::None) } else { (parse_num(n), if d == "L" { Turn::Left } else { Turn::Right }) })
-        .collect();
+        .map(|(n, d)| {
+            let d = match d {
+                "L" => Turn::Left,
+                "R" => Turn::Right,
+                _ => Turn::None,
+            };
+            (parse_num(n), d)
+        })
+        .collect_vec();
+    debug_assert_eq!(moves.iter().filter(|(_, d)| matches!(d, Turn::None)).count(), 1, "Only the last entry should have no turn");
     (grid, moves)
 }
 fn part1((grid, instructions): &Parsed) -> i64 {
     let mut pos = *grid.fields.keys().filter(|p| p.0[0] == 1).min_by_key(|p| p.0[1]).unwrap();
     let mut dir = Direction::Right;
-    let mut grid2 = grid.clone();
-    grid2[pos] = Field::Me;
-    println!("{}", draw_ascii(&grid2.fields));
     for &(steps, turn) in instructions {
         for _ in 0..steps {
             let next = PositionND::from(match dir {
@@ -70,12 +75,10 @@ fn part1((grid, instructions): &Parsed) -> i64 {
                 Direction::Left => [0, -1],
                 Direction::Right => [0, 1],
             }) + pos;
-            // dbg!(steps, pos, dir, next);
             pos = match grid.get(&next) {
                 Some(Field::Wall) => break,
                 Some(_) => next,
                 None => {
-                    println!("Wrapping from {pos:?} in direction {dir:?}");
                     let (&new_pos, &wall) = match dir {
                         Direction::Up => grid.fields.iter().filter(|(p, _)| p.0[1] == pos.0[1]).max_by_key(|(p, _)| p.0[0]),
                         Direction::Down => grid.fields.iter().filter(|(p, _)| p.0[1] == pos.0[1]).min_by_key(|(p, _)| p.0[0]),
@@ -97,6 +100,7 @@ fn part1((grid, instructions): &Parsed) -> i64 {
             (d, Turn::Left) => d + -1,
         };
     }
+    println!("{pos:?}, {dir:?}");
     pos.0[0] * 1000 + pos.0[1] * 4 + (dir as i64)
 }
 
@@ -118,12 +122,13 @@ boilerplate! {
         .#......
         ......#.
 
-10R5L5R10L4R5L5",
+10R5L5R10L4R5L5
+",
     tests: {
         part1: { TEST_INPUT => 6032 },
         part2: { TEST_INPUT => 0 },
     },
-    bench1 == 0, // 123047 too high
+    bench1 == 123046,
     bench2 == 0,
     bench_parse: |(g, i): &Parsed| g.len() + i.len() => 17001,
 }