From 9b84f5b0d90676aa8e578d367e7870c86a4ebf3b Mon Sep 17 00:00:00 2001
From: Jesse Luehrs <doy@tozt.net>
Date: Mon, 11 Dec 2023 00:33:35 -0500
Subject: day 11

---
 src/bin/2023/day11.rs | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/bin/2023/main.rs  |  2 ++
 2 files changed, 96 insertions(+)
 create mode 100644 src/bin/2023/day11.rs

(limited to 'src/bin')

diff --git a/src/bin/2023/day11.rs b/src/bin/2023/day11.rs
new file mode 100644
index 0000000..885a99b
--- /dev/null
+++ b/src/bin/2023/day11.rs
@@ -0,0 +1,94 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+use advent_of_code::prelude::*;
+
+pub fn parse(fh: File) -> Result<Grid<bool>> {
+    Ok(parse::grid(parse::raw_lines(fh), |c, _, _| c == b'#'))
+}
+
+pub fn part1(mut map: Grid<bool>) -> Result<i64> {
+    let mut expand_rows = vec![];
+    for row in map.each_row() {
+        if map[row].iter().all(|b| !b) {
+            expand_rows.push(row);
+        }
+    }
+    let mut expand_cols = vec![];
+    for col in map.each_col() {
+        if map.each_row().map(|row| map[row][col]).all(|b| !b) {
+            expand_cols.push(col);
+        }
+    }
+    for row in expand_rows.into_iter().rev() {
+        map.insert_row(row);
+    }
+    for col in expand_cols.into_iter().rev() {
+        map.insert_col(col);
+    }
+
+    let galaxies: HashSet<(Row, Col)> = map
+        .indexed_cells()
+        .filter_map(|(pos, galaxy)| if *galaxy { Some(pos) } else { None })
+        .collect();
+
+    let mut total = 0;
+    for a in &galaxies {
+        for b in &galaxies {
+            total += a.0.abs_diff(b.0).0 + a.1.abs_diff(b.1).0
+        }
+    }
+
+    Ok((total / 2).try_into().unwrap())
+}
+
+pub fn part2(map: Grid<bool>) -> Result<i64> {
+    let mut expand_rows = vec![];
+    for row in map.each_row() {
+        if map[row].iter().all(|b| !b) {
+            expand_rows.push(row);
+        }
+    }
+    let mut expand_cols = vec![];
+    for col in map.each_col() {
+        if map.each_row().map(|row| map[row][col]).all(|b| !b) {
+            expand_cols.push(col);
+        }
+    }
+
+    let galaxies: HashSet<(Row, Col)> = map
+        .indexed_cells()
+        .filter_map(|(pos, galaxy)| if *galaxy { Some(pos) } else { None })
+        .collect();
+
+    let mut total = 0;
+    for a in &galaxies {
+        for b in &galaxies {
+            let expanded_rows = expand_rows
+                .iter()
+                .filter(|row| (a.0.min(b.0)..a.0.max(b.0)).contains(row))
+                .count();
+            let expanded_cols = expand_cols
+                .iter()
+                .filter(|col| (a.1.min(b.1)..a.1.max(b.1)).contains(col))
+                .count();
+            total += a.0.abs_diff(b.0).0
+                + a.1.abs_diff(b.1).0
+                + 999999 * (expanded_rows + expanded_cols);
+        }
+    }
+
+    Ok((total / 2).try_into().unwrap())
+}
+
+#[test]
+fn test() {
+    assert_eq!(
+        part1(parse(parse::data(2023, 11).unwrap()).unwrap()).unwrap(),
+        10033566
+    );
+    assert_eq!(
+        part2(parse(parse::data(2023, 11).unwrap()).unwrap()).unwrap(),
+        560822911938
+    );
+}
diff --git a/src/bin/2023/main.rs b/src/bin/2023/main.rs
index c6f9207..44c0ff0 100644
--- a/src/bin/2023/main.rs
+++ b/src/bin/2023/main.rs
@@ -21,6 +21,7 @@ mod day7;
 mod day8;
 mod day9;
 mod day10;
+mod day11;
 // NEXT MOD
 
 #[paw::main]
@@ -37,6 +38,7 @@ fn main(opt: Opt) -> Result<()> {
         8 => advent_of_code::day!(2023, opt.day, opt.puzzle, day8),
         9 => advent_of_code::day!(2023, opt.day, opt.puzzle, day9),
         10 => advent_of_code::day!(2023, opt.day, opt.puzzle, day10),
+        11 => advent_of_code::day!(2023, opt.day, opt.puzzle, day11),
         // NEXT PART
         _ => panic!("unknown day {}", opt.day),
     }
-- 
cgit v1.2.3-54-g00ecf