From 8cb6a0fee2bb7d213db1063ecc5e30e86adc8c11 Mon Sep 17 00:00:00 2001
From: Ashhhleyyy <ash@ashhhleyyy.dev>
Date: Wed, 6 Dec 2023 23:51:29 +0000
Subject: [PATCH] feat: day 5 part 2 (this took <10mins on the 128 core uni
 compute server)

---
 src/bin/day_5.rs | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/bin/day_5.rs b/src/bin/day_5.rs
index e2c791c..600b8a7 100644
--- a/src/bin/day_5.rs
+++ b/src/bin/day_5.rs
@@ -1,4 +1,5 @@
 use aoc_2022::prelude::*;
+use color_eyre::eyre::ContextCompat;
 use rayon::prelude::*;
 
 type Input = Almanac;
@@ -53,13 +54,32 @@ fn day_5(mut input: Input) -> Result<()> {
             }
         }
         current_position
-    }).min();
+    }).min().wrap_err("missing result")?;
 
-    println!("{result:?}");
+    println!("{result}");
 
     // Part 2
     println!("Part two: ");
 
+    let result = input.seeds.chunks_exact(2).flat_map(|range| {
+        let range_start = range[0];
+        let range_length = range[1];
+        (0..range_length).map(move |s| s + range_start)
+    }).par_bridge().map(|seed| {
+        let mut current_position = seed;
+        for ranges in &input.maps {
+            let range = ranges.iter().filter(|(_, src_start, length)| {
+                current_position >= *src_start && (current_position - *src_start) < *length
+            }).next();
+            if let Some((dest_start, src_start, _)) = range {
+                current_position = dest_start + (current_position - src_start);
+            }
+        }
+        current_position
+    }).min().wrap_err("there should be a result")?;
+
+    println!("{result}");
+
     // let result = input.seeds.chunks_exact(2).map(|range| {
     //     let range_start = range[0];
     //     let range_length = range[1];