From ee741775fec92f06567621e451859632db2818c6 Mon Sep 17 00:00:00 2001
From: Sijmen Schoon <me@sijmenschoon.nl>
Date: Sat, 26 Dec 2020 00:33:18 +0100
Subject: [PATCH] rust: Improve benchmarks and optimize day 6 a little

---
 README.md         | 32 ++++++++++++++++----------------
 rust/src/day06.rs |  6 ++++--
 rust/src/main.rs  |  5 +++--
 3 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/README.md b/README.md
index 1bbd720..ff4ec35 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ Days 6 and 12 are missing because I did them in IPython and never bothered putti
 |   22 |       |   ✔️   |            |
 |   23 |   ✔️  |   ✔️   |            |
 |   24 |       |   ✔️   |            |
-|   25 |       |        |            |
+|   25 |   ✔️  |        |            |
 
 
 ## Benchmarks (Rust)
@@ -39,29 +39,29 @@ I'm somewhat trying to do the <1 second challenge, but I've been a bit short on
 
 |        Day |         Time |
 | ---------: | -----------: |
-|          1 |     111.14µs |
-|          2 |     110.91µs |
-|          3 |      58.66µs |
-|          4 |     280.38µs |
-|          5 |      65.60µs |
-|          6 |            - |
+|          1 |     112.46µs |
+|          2 |     113.41µs |
+|          3 |      60.96µs |
+|          4 |     286.32µs |
+|          5 |      73.25µs |
+|          6 |      78.59µs |
 |          7 |            - |
-|          8 |     168.35µs |
-|          9 |      45.37µs |
+|          8 |     170.56µs |
+|          9 |      46.69µs |
 |         10 |            - |
 |         11 |            - |
 |         12 |            - |
 |         13 |            - |
 |         14 |            - |
-|         15 |  475441.39µs |
-|         16 |     338.97µs |
-|         17 |   69548.73µs |
+|         15 |  459975.24µs |
+|         16 |     344.11µs |
+|         17 |   70782.00µs |
 |         18 |            - |
-|         19 |     398.30µs |
+|         19 |     403.49µs |
 |         20 |            - |
 |         21 |            - |
 |         22 |            - |
-|         23 |  196018.58µs |
+|         23 |  195819.54µs |
 |         24 |            - |
-|         25 |   26280.61µs |
-| **Total:** |    768.867ms |
+|         25 |   26266.60µs |
+| **Total:** |    754.533ms |
diff --git a/rust/src/day06.rs b/rust/src/day06.rs
index 45dd10b..acd916a 100644
--- a/rust/src/day06.rs
+++ b/rust/src/day06.rs
@@ -13,7 +13,7 @@ pub fn run(print: bool) -> Duration {
     let mut part1 = 0;
     let mut part2 = 0;
 
-    for group in file_string.trim().split("\n\n") {
+    for group in file_string.split("\n\n") {
         let mut set = 0u32;
         for c in group.chars().filter(|c| c.is_alphabetic()) {
             set |= 1 << (c as usize - 'a' as usize);
@@ -29,7 +29,9 @@ pub fn run(print: bool) -> Duration {
                 line_set |= 1 << (c as usize - 'a' as usize);
             }
         }
-        set &= line_set;
+        if line_set != 0 {
+            set &= line_set;
+        }
         part2 += count_bits(set);
     }
 
diff --git a/rust/src/main.rs b/rust/src/main.rs
index 896ce08..2eec5fc 100644
--- a/rust/src/main.rs
+++ b/rust/src/main.rs
@@ -73,12 +73,13 @@ fn main() {
             }
 
             let repetitions =
-                5000.min((Duration::new(2, 0).as_nanos() / first_run.as_nanos()) as u32);
+                100000.min((Duration::new(5, 0).as_nanos() / first_run.as_nanos()) as u32);
 
             let mut elapsed = Duration::new(0, 0);
             for _ in 0..repetitions {
-                elapsed += days[day](false) / repetitions;
+                elapsed += days[day](false);
             }
+            elapsed /= repetitions;
             println!("|         {:>2} | {:>10.2}µs |", day + 1, elapsed.as_secs_f64() * 1_000_000.0);
             total += elapsed;
         }