Much faster approach taking advantage of the sparse nature of the binomial coefficients

maneatingape · maneatingape · commit eb38d0bb1591 · 2025-11-04T16:38:07.000Z
diff --git a/README.md b/README.md
@@ -1,7 +1,7 @@
 # Advent of Code [![checks-badge]][checks-link] [![docs-badge]][docs-link]
 
 Blazing fast Rust solutions for every [Advent of Code] puzzle from 2015 to 2024, taking
-**471 milliseconds** to solve all 500 stars. Each solution is carefully optimized for performance
+**470 milliseconds** to solve all 500 stars. Each solution is carefully optimized for performance
 while ensuring the code remains concise, readable, and idiomatic.
 
 ## Features
@@ -67,7 +67,7 @@ Performance is reasonable even on older hardware, for example a 2011 MacBook Pro
 
 | Year | [2015](#2015) | [2016](#2016) | [2017](#2017) | [2018](#2018) | [2019](#2019) | [2020](#2020) | [2021](#2021) | [2022](#2022) | [2023](#2023) | [2024](#2024) |
 | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
-| Benchmark (ms) | 14 | 109 | 57 | 35 | 14 | 220 | 8 | 5 | 5 | 4 |
+| Benchmark (ms) | 14 | 109 | 57 | 35 | 13 | 220 | 8 | 5 | 5 | 4 |
 
 ## 2024
 
@@ -250,7 +250,7 @@ Performance is reasonable even on older hardware, for example a 2011 MacBook Pro
 | 13 | [Care Package](https://adventofcode.com/2019/day/13) | [Source](src/year2019/day13.rs) | 2527 |
 | 14 | [Space Stoichiometry](https://adventofcode.com/2019/day/14) | [Source](src/year2019/day14.rs) | 17 |
 | 15 | [Oxygen System](https://adventofcode.com/2019/day/15) | [Source](src/year2019/day15.rs) | 291 |
-| 16 | [Flawed Frequency Transmission](https://adventofcode.com/2019/day/16) | [Source](src/year2019/day16.rs) | 1956 |
+| 16 | [Flawed Frequency Transmission](https://adventofcode.com/2019/day/16) | [Source](src/year2019/day16.rs) | 224 |
 | 17 | [Set and Forget](https://adventofcode.com/2019/day/17) | [Source](src/year2019/day17.rs) | 338 |
 | 18 | [Many-Worlds Interpretation](https://adventofcode.com/2019/day/18) | [Source](src/year2019/day18.rs) | 1039 |
 | 19 | [Tractor Beam](https://adventofcode.com/2019/day/19) | [Source](src/year2019/day19.rs) | 688 |
diff --git a/docs/pie-2019.svg b/docs/pie-2019.svg
@@ -1,10 +1,9 @@
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+%%{init: {"themeVariables": { "pie1": "#c6cdd5", "pie2": "#7cb5ec", "pie3": "#90ed7d", "pie4": "#f7a35c"}}}%%
 pie
     title Year 2019 benchmark time by % of total
-    "Others" : 5981
+    "Others" : 6206
     "Day 13" : 2460
-    "Day 16" : 1949
     "Day 25" : 1890
     "Day 21" : 1674
 -->
@@ -18,35 +17,29 @@ pie
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diff --git a/src/year2019/day16.rs b/src/year2019/day16.rs
