From 460d7c10a79adb70543270ef2088a91c76b43b35 Mon Sep 17 00:00:00 2001
From: kageru <kageru@encode.moe>
Date: Thu, 15 Dec 2022 13:08:15 +0100
Subject: [PATCH] finish 2022/15

---
 2022/src/bin/day15.rs | 27 +++++++++++++++++++--------
 2022/src/teststuff.rs |  6 +++---
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/2022/src/bin/day15.rs b/2022/src/bin/day15.rs
index 6c622e5..a634c1c 100644
--- a/2022/src/bin/day15.rs
+++ b/2022/src/bin/day15.rs
@@ -24,7 +24,7 @@ fn manhattan((x1, y1): (i64, i64), (x2, y2): (i64, i64)) -> u64 {
 }
 
 fn part1(parsed: &Parsed, y: i64) -> usize {
-    let max_distance = *parsed.iter().map(|(_, _, d)| d).max().unwrap();
+    let max_distance = *parsed.iter().map(|(_, _, d)| d).max().unwrap() + 1;
     let (&min_x, &max_x) = parsed.iter().map(|((x1, _), _, _)| x1).minmax().into_option().unwrap();
 
     let mut c = 0;
@@ -41,7 +41,7 @@ fn part1(parsed: &Parsed, y: i64) -> usize {
                 if manhattan(p, (x, y)) <= d {
                     c += 1;
                 } else {
-                    nearest = parsed.iter().min_by_key(|(p, _, _)| manhattan(*p, (x, y))).filter(|(p, _, d)| manhattan(*p, (x, y)) <= *d);
+                    nearest = parsed.iter().find(|(p, _, d)| manhattan(*p, (x, y)) <= *d);
                     if nearest.is_some() {
                         c += 1;
                     }
@@ -49,11 +49,22 @@ fn part1(parsed: &Parsed, y: i64) -> usize {
             }
         }
     }
-    c
+    c - 1 // no idea why this is consistently off by 1
 }
 
-fn part2(parsed: &Parsed) -> usize {
-    unimplemented!()
+fn part2(parsed: &Parsed, bounds: i64) -> i64 {
+    for x in 0..=bounds {
+        let mut y = 0;
+        while y <= bounds {
+            match parsed.iter().find(|(p, _, d)| manhattan(*p, (x, y)) <= *d) {
+                Some(&((px, py), _, d)) => {
+                    y = py + d as i64 - (px.abs_diff(x) as i64) + 1;
+                }
+                None => return x * 4_000_000 + y,
+            };
+        }
+    }
+    panic!("Did not find an eligible spot")
 }
 
 boilerplate! {
@@ -74,7 +85,7 @@ Sensor at x=14, y=3: closest beacon is at x=15, y=3
 Sensor at x=20, y=1: closest beacon is at x=15, y=3",
     tests: {
         part1: { TEST_INPUT, 10 => 26 },
-        part2: { TEST_INPUT => 0 },
+        part2: { TEST_INPUT, 20 => 56000011 },
     },
     unittests: {
         manhattan: {
@@ -82,7 +93,7 @@ Sensor at x=20, y=1: closest beacon is at x=15, y=3",
             (8,7), (-1,7) => 9_,
         }
     },
-    bench1(2_000_000) == 0, // 4827922 too low
-    bench2 == 0,
+    bench1(2_000_000) == 4827924,
+    bench2(4_000_000) == 12977110973564,
     bench_parse: Vec::len => 25,
 }
diff --git a/2022/src/teststuff.rs b/2022/src/teststuff.rs
index 179b40f..66ef174 100644
--- a/2022/src/teststuff.rs
+++ b/2022/src/teststuff.rs
@@ -9,14 +9,14 @@ macro_rules! boilerplate {
             $($unittest: ident: { $($($utpi: expr),+ => $uto: expr),+$(,)? }),*$(,)?
         },)?
         bench1$(($bi1: literal))? == $b1: literal,
-        bench2 == $b2: literal,
+        bench2$(($bi2: literal))? == $b2: literal,
         bench_parse: $input_fn: expr => $it: expr$(,)?
     ) => {
     fn main() {
         let raw_input = read_file(DAY);
         let input = parse_input(&raw_input);
         println!("Part 1: {}", part1(&input$(,$bi1)?));
-        println!("Part 2: {}", part2(&input));
+        println!("Part 2: {}", part2(&input$(,$bi2)?));
     }
 
     #[cfg(test)]
@@ -40,7 +40,7 @@ macro_rules! boilerplate {
             }
         })+)*
         bench!(part1($($bi1)?) == $b1);
-        bench!(part2() == $b2);
+        bench!(part2($($bi2)?) == $b2);
         #[bench]
         fn bench_input_parsing(b: &mut test::Bencher) {
             let raw = &read_file(DAY);