I love large numbers

Cargo.lock

@@ -22,6 +22,9 @@ name = "advent"
 version = "0.1.0"
 dependencies = [
  "clap",
+ "num-bigint",
+ "num-irrational",
+ "num-rational",
  "regex",
  "reqwest",
  "scraper",
@@ -35,7 +38,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "91429305e9f0a25f6205c5b8e0d2db09e0708a7a6df0f42212bb56c32c8ac97a"
 dependencies = [
  "cfg-if",
- "getrandom 0.2.11",
+ "getrandom",
  "once_cell",
  "version_check",
  "zerocopy",
@@ -241,7 +244,7 @@ dependencies = [
  "cssparser-macros",
  "dtoa-short",
  "itoa",
- "phf 0.8.0",
+ "phf",
  "smallvec",
 ]
 
@@ -415,17 +418,6 @@ dependencies = [
  "unicode-width",
 ]
 
-[[package]]
-name = "getrandom"
-version = "0.1.16"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
-dependencies = [
- "cfg-if",
- "libc",
- "wasi 0.9.0+wasi-snapshot-preview1",
-]
-
 [[package]]
 name = "getrandom"
 version = "0.2.11"
@@ -434,7 +426,7 @@ checksum = "fe9006bed769170c11f845cf00c7c1e9092aeb3f268e007c3e760ac68008070f"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
@@ -653,7 +645,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a2629bb1404f3d34c2e921f21fd34ba00b206124c81f65c50b43b6aaefeb016"
 dependencies = [
  "log",
- "phf 0.10.1",
+ "phf",
  "phf_codegen",
  "string_cache",
  "string_cache_codegen",
@@ -688,7 +680,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dce281c5e46beae905d4de1870d8b1509a9142b62eedf18b443b011ca8343d0"
 dependencies = [
  "libc",
- "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasi",
  "windows-sys 0.48.0",
 ]
 
@@ -716,6 +708,60 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e4a24736216ec316047a1fc4252e27dabb04218aa4a3f37c6e7ddbf1f9782b54"
 
+[[package]]
+name = "num-bigint"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "608e7659b5c3d7cba262d894801b9ec9d00de989e8a82bd4bef91d08da45cdc0"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-irrational"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa0f32746f69c782504c52e5baf85243acd5205f83ef6186ffc79a404a62ebdd"
+dependencies = [
+ "num-bigint",
+ "num-integer",
+ "num-rational",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0638a1c9d0a3c0914158145bc76cff373a75a627e6ecbfb71cbe6f453a5a19b0"
+dependencies = [
+ "autocfg",
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.16.0"
@@ -814,24 +860,15 @@ version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
-[[package]]
-name = "phf"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3dfb61232e34fcb633f43d12c58f83c1df82962dcdfa565a4e866ffc17dafe12"
-dependencies = [
- "phf_macros",
- "phf_shared 0.8.0",
- "proc-macro-hack",
-]
-
 [[package]]
 name = "phf"
 version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fabbf1ead8a5bcbc20f5f8b939ee3f5b0f6f281b6ad3468b84656b658b455259"
 dependencies = [
- "phf_shared 0.10.0",
+ "phf_macros",
+ "phf_shared",
+ "proc-macro-hack",
 ]
 
 [[package]]
@@ -840,18 +877,8 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fb1c3a8bc4dd4e5cfce29b44ffc14bedd2ee294559a294e2a4d4c9e9a6a13cd"
 dependencies = [
- "phf_generator 0.10.0",
- "phf_shared 0.10.0",
-]
-
-[[package]]
-name = "phf_generator"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17367f0cc86f2d25802b2c26ee58a7b23faeccf78a396094c13dced0d0182526"
-dependencies = [
- "phf_shared 0.8.0",
- "rand 0.7.3",
+ "phf_generator",
+ "phf_shared",
 ]
 
 [[package]]
@@ -860,33 +887,24 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5d5285893bb5eb82e6aaf5d59ee909a06a16737a8970984dd7746ba9283498d6"
 dependencies = [
- "phf_shared 0.10.0",
- "rand 0.8.5",
+ "phf_shared",
+ "rand",
 ]
 
 [[package]]
 name = "phf_macros"
-version = "0.8.0"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f6fde18ff429ffc8fe78e2bf7f8b7a5a5a6e2a8b58bc5a9ac69198bbda9189c"
+checksum = "58fdf3184dd560f160dd73922bea2d5cd6e8f064bf4b13110abd81b03697b4e0"
 dependencies = [
- "phf_generator 0.8.0",
- "phf_shared 0.8.0",
+ "phf_generator",
+ "phf_shared",
  "proc-macro-hack",
  "proc-macro2",
  "quote",
  "syn 1.0.109",
 ]
 
-[[package]]
-name = "phf_shared"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c00cf8b9eafe68dde5e9eaa2cef8ee84a9336a47d566ec55ca16589633b65af7"
-dependencies = [
- "siphasher",
-]
-
 [[package]]
 name = "phf_shared"
 version = "0.10.0"
@@ -950,20 +968,6 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "rand"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
-dependencies = [
- "getrandom 0.1.16",
- "libc",
- "rand_chacha 0.2.2",
- "rand_core 0.5.1",
- "rand_hc",
- "rand_pcg",
-]
-
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -971,18 +975,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
  "libc",
- "rand_chacha 0.3.1",
- "rand_core 0.6.4",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
-dependencies = [
- "ppv-lite86",
- "rand_core 0.5.1",
+ "rand_chacha",
+ "rand_core",
 ]
 
 [[package]]
@@ -992,16 +986,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core 0.6.4",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
-dependencies = [
- "getrandom 0.1.16",
+ "rand_core",
 ]
 
 [[package]]
@@ -1010,25 +995,7 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 dependencies = [
- "getrandom 0.2.11",
-]
-
-[[package]]
-name = "rand_hc"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
-dependencies = [
- "rand_core 0.5.1",
-]
-
-[[package]]
-name = "rand_pcg"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16abd0c1b639e9eb4d7c50c0b8100b0d0f849be2349829c740fe8e6eb4816429"
-dependencies = [
- "rand_core 0.5.1",
+ "getrandom",
 ]
 
 [[package]]
@@ -1198,7 +1165,7 @@ dependencies = [
  "fxhash",
  "log",
  "new_debug_unreachable",
- "phf 0.10.1",
+ "phf",
  "phf_codegen",
  "precomputed-hash",
  "servo_arc",
@@ -1313,7 +1280,7 @@ dependencies = [
  "new_debug_unreachable",
  "once_cell",
  "parking_lot",
- "phf_shared 0.10.0",
+ "phf_shared",
  "precomputed-hash",
  "serde",
 ]
@@ -1324,8 +1291,8 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6bb30289b722be4ff74a408c3cc27edeaad656e06cb1fe8fa9231fa59c728988"
 dependencies = [
- "phf_generator 0.10.0",
- "phf_shared 0.10.0",
+ "phf_generator",
+ "phf_shared",
  "proc-macro2",
  "quote",
 ]
@@ -1572,12 +1539,6 @@ dependencies = [
  "try-lock",
 ]
 
-[[package]]
-name = "wasi"
-version = "0.9.0+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
-
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"

Cargo.toml

@@ -7,6 +7,9 @@ edition = "2021"
 
 [dependencies]
 clap = { version = "4.4.10", features = ["derive"] }
+num-bigint = "0.4.4"
+num-irrational = { version = "0.3.0", features = ["num-bigint"] }
+num-rational = { version = "0.4.1", features = ["num-bigint"] }
 regex = "1.10.2"
 reqwest = "0.11.22"
 scraper = "0.18.1"

src/day6/mod.rs

@@ -1,3 +1,8 @@
+use std::str::FromStr;
+
+use num_bigint::BigInt;
+use num_irrational::QuadraticSurd;
+
 use crate::utils::Day;
 
 #[derive(Debug, Default)]
@@ -8,7 +13,7 @@ pub struct Day6 {
 impl Day for Day6 {
     fn part1(&mut self) -> String {
         let lines = self.input.lines().map(|l| l.split_ascii_whitespace().skip(1).collect::<Vec<_>>()).collect::<Vec<_>>();
-        let races = [
+        let races: [(f64, f64); 4] = [
             (lines[0][0].parse().unwrap(), lines[1][0].parse().unwrap()),
             (lines[0][1].parse().unwrap(), lines[1][1].parse().unwrap()),
             (lines[0][2].parse().unwrap(), lines[1][2].parse().unwrap()),
@@ -18,13 +23,16 @@ impl Day for Day6 {
         let mut acc = 1usize;
 
         for (time, record_distance) in races {
-            let mut wins = 0usize;
-            for time_holding_button in 0..time {
-                let distance = (time - time_holding_button) * time_holding_button /* velocity */;
-                if distance > record_distance { wins += 1; }
-            }
+            // let mut wins = 0usize;
+            // for time_holding_button in 0..time {
+            //     let distance = (time - time_holding_button) * time_holding_button /* velocity */;
+            //     if distance > record_distance { wins += 1; }
+            // }
+            // Mathy solution:
+            let b = ((time+((time*time-4.0*record_distance).sqrt())) / 2.0).ceil();
+            let a = ((time-((time*time-4.0*record_distance).sqrt())) / 2.0).ceil();
 
-            acc *= wins;
+            acc *= (b - a) as usize;
         }
 
         acc.to_string()
@@ -33,13 +41,27 @@ impl Day for Day6 {
     fn part2(&mut self) -> String {
         let lines = self.input.lines().map(|l| l[10..].split_ascii_whitespace().collect::<String>()).collect::<Vec<_>>();
 
-        let (time, record_distance): (u128, u128) = (lines[0].parse().unwrap(), lines[1].parse().unwrap());
-        let mut wins = 0u128;
-        for time_holding_button in 0..time {
-            let distance = (time - time_holding_button) * time_holding_button /* velocity */;
-            if distance > record_distance { wins += 1; }
-        }
+        // Boring solution:
+        // let mut wins = 0u128;
+        // for time_holding_button in 0..time {
+        //     let distance = (time - time_holding_button) * time_holding_button /* velocity */;
+        //     if distance > record_distance { wins += 1; }
+        // }
 
-        wins.to_string()
+        // wins.to_string()
+        // Mathy solution:
+        // let b = ((time+((time*time-4.0*record_distance).sqrt())) / 2.0).ceil();
+        // let a = ((time-((time*time-4.0*record_distance).sqrt())) / 2.0).ceil();
+
+        // (b - a).to_string()
+        // Arbitrary precision solution:
+        let lower = QuadraticSurd::from_equation(
+            Into::<BigInt>::into(-1).into(),
+            BigInt::from_str(&lines[0]).unwrap().into(),
+            BigInt::from_str(&("-".to_string() + &lines[1])).unwrap().into()
+        ).unwrap();
+        let higher = lower.conj_ref();
+
+        ((higher - lower).floor().to_integer().value() + 1u8).to_string()
     }
 }

src/main.rs

@@ -39,6 +39,9 @@ enum Subcommands {
         /// If used, then the example input will be solved and checked rather than the real one
         #[arg(short, long)]
         example: bool,
+        /// If used, then the custom input will be solved and checked rather than the real one
+        #[arg(short, long)]
+        custom: bool,
     },
     /// Runs solution N amount of times, averaging speed
     Benchmark {
@@ -71,9 +74,12 @@ async fn main() {
     let client = reqwest::Client::new();
 
     match cli.subcommand {
-        Subcommands::Solve { day, part, example } => {
+        Subcommands::Solve { day, part, example, custom } => {
             let (input, solution) = match example {
-                false => (fetcher::fetch_input(cli.auth, day).await, None),
+                false => match custom {
+                    false => (fetcher::fetch_input(cli.auth, day).await, None),
+                    true => (include_str!("input.txt").to_string(), None)
+                },
                 true => {
                     let example = fetcher::fetch_example(cli.auth, day, part).await;
                     (example.0, Some(example.1))