From cab8962911ca83adf82b432d9f27e28c28305aa8 Mon Sep 17 00:00:00 2001
From: Malte Tammena <malte.tammena@pm.me>
Date: Sun, 25 Dec 2022 09:47:27 +0100
Subject: [PATCH] Solve first part of day25

---
 Cargo.lock        |  63 ++++++++++--------
 Cargo.toml        |   2 +-
 day25/Cargo.toml  |  10 +++
 day25/input       | 116 ++++++++++++++++++++++++++++++++
 day25/input.test  |  13 ++++
 day25/src/main.rs | 165 ++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 340 insertions(+), 29 deletions(-)
 create mode 100644 day25/Cargo.toml
 create mode 100644 day25/input
 create mode 100644 day25/input.test
 create mode 100644 day25/src/main.rs

diff --git a/Cargo.lock b/Cargo.lock
index f1371a8..41e2869 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -30,9 +30,9 @@ checksum = "2dbdbb2877d26e0647c6b8125802b2ecf2dc2a28d864dde41e6f9b9a54da08fe"
 
 [[package]]
 name = "async-trait"
-version = "0.1.59"
+version = "0.1.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "31e6e93155431f3931513b243d371981bb2770112b370c82745a1d19d2f99364"
+checksum = "677d1d8ab452a3936018a687b20e6f7cf5363d713b732b8884001317b0e48aa3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -129,9 +129,9 @@ checksum = "3a4f925191b4367301851c6d99b09890311d74b0d43f274c0b34c86d308a3663"
 
 [[package]]
 name = "cc"
-version = "1.0.77"
+version = "1.0.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9f73505338f7d905b19d18738976aae232eb46b8efc15554ffc56deb5d9ebe4"
+checksum = "a20104e2335ce8a659d6dd92a51a767a0c062599c73b343fd152cb401e828c3d"
 
 [[package]]
 name = "cfg-if"
@@ -141,9 +141,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clap"
-version = "4.0.29"
+version = "4.0.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d63b9e9c07271b9957ad22c173bae2a4d9a81127680962039296abcd2f8251d"
+checksum = "a7db700bc935f9e43e88d00b0850dae18a63773cfbec6d8e070fccf7fef89a39"
 dependencies = [
  "bitflags",
  "clap_derive",
@@ -179,9 +179,9 @@ dependencies = [
 
 [[package]]
 name = "colorous"
-version = "1.0.8"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "882e392738ed515520f38708166e9efec85ee154f80bf1fc64510e2fc54bf481"
+checksum = "2875caafcad10de47ec09ead140f27a276a25b0b2f553cec9b2152194b96bf5d"
 
 [[package]]
 name = "darling"
@@ -376,6 +376,13 @@ version = "0.1.0"
 [[package]]
 name = "day24"
 version = "0.1.0"
+dependencies = [
+ "bitvec",
+]
+
+[[package]]
+name = "day25"
+version = "0.1.0"
 
 [[package]]
 name = "errno"
@@ -539,9 +546,9 @@ dependencies = [
 
 [[package]]
 name = "is-terminal"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "927609f78c2913a6f6ac3c27a4fe87f43e2a35367c0c4b0f8265e8f49a104330"
+checksum = "28dfb6c8100ccc63462345b67d1bbc3679177c75ee4bf59bf29c8b1d110b8189"
 dependencies = [
  "hermit-abi",
  "io-lifetimes",
@@ -586,15 +593,15 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.138"
+version = "0.2.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db6d7e329c562c5dfab7a46a2afabc8b987ab9a4834c9d1ca04dc54c1546cef8"
+checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.1.3"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f9f08d8963a6c613f4b1a78f4f4a4dbfadf8e6545b2d72861731e4858b8b47f"
+checksum = "f051f77a7c8e6957c0696eac88f26b0117e54f52d3fc682ab19397a8812846a4"
 
 [[package]]
 name = "logos"
@@ -687,18 +694,18 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.47"
+version = "1.0.49"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ea3d908b0e36316caf9e9e2c4625cdde190a7e6f440d794667ed17a1855e725"
+checksum = "57a8eca9f9c4ffde41714334dee777596264c7825420f521abc92b5b5deb63a5"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.21"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
+checksum = "8856d8364d252a14d474036ea1358d63c9e6965c8e5c1885c18f73d70bff9c7b"
 dependencies = [
  "proc-macro2",
 ]
@@ -799,9 +806,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.150"
+version = "1.0.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e326c9ec8042f1b5da33252c8a37e9ffbd2c9bef0155215b6e6c80c790e05f91"
+checksum = "97fed41fc1a24994d044e6db6935e69511a1153b52c15eb42493b26fa87feba0"
 
 [[package]]
 name = "smallvec"
@@ -820,9 +827,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.105"
+version = "1.0.107"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "60b9b43d45702de4c839cb9b51d9f529c5dd26a4aff255b42b1ebc03e88ee908"
+checksum = "1f4064b5b16e03ae50984a5a8ed5d4f8803e6bc1fd170a3cda91a1be4b18e3f5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -868,18 +875,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.37"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10deb33631e3c9018b9baf9dcbbc4f737320d2b576bac10f6aefa048fa407e3e"
+checksum = "6a9cd18aa97d5c45c6603caea1da6628790b37f7a34b6ca89522331c5180fed0"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.37"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "982d17546b47146b28f7c22e3d08465f6b8903d0ea13c1660d9d84a6e7adcdbb"
+checksum = "1fb327af4685e4d03fa8cbcf1716380da910eeb2bb8be417e7f9fd3fb164f36f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -911,9 +918,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.5"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ceab39d59e4c9499d4e5a8ee0e2735b891bb7308ac83dfb4e80cad195c9f6f3"
+checksum = "84a22b9f218b40614adcb3f4ff08b703773ad44fa9423e4e0d346d5db86e4ebc"
 
 [[package]]
 name = "version_check"
diff --git a/Cargo.toml b/Cargo.toml
index cb76fbe..2c6baae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,5 @@
 [workspace]
-members = [ "day01", "day01-gen-problem", "day02", "day02-gen-problem", "day03", "day03-gen-problem", "day04", "day05", "day06", "day07", "day08", "day09", "day10", "day11", "day12", "day12-tim", "day13", "day14", "day15", "day16", "day17", "day18", "day19", "day20", "day21", "day22", "day23", "day24", ]
+members = [ "day01", "day01-gen-problem", "day02", "day02-gen-problem", "day03", "day03-gen-problem", "day04", "day05", "day06", "day07", "day08", "day09", "day10", "day11", "day12", "day12-tim", "day13", "day14", "day15", "day16", "day17", "day18", "day19", "day20", "day21", "day22", "day23", "day24", "day25", ]
 
 [profile.release]
 #debug = true
diff --git a/day25/Cargo.toml b/day25/Cargo.toml
new file mode 100644
index 0000000..3b2f2b9
--- /dev/null
+++ b/day25/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "day25"
+version = "0.1.0"
+edition = "2021"
+
+[package.metadata.nix]
+build = true
+app = true
+
+[dependencies]
diff --git a/day25/input b/day25/input
new file mode 100644
index 0000000..4837f2e
--- /dev/null
+++ b/day25/input
@@ -0,0 +1,116 @@
+1-12212=-=--=0221
+1----2-1
+1=2==-1-1=1-02---
+220--0=2-01-
+2=02-101-2-0221
+10=-21-
+1-02-0-10=0002
+20
+1==0-
+22-1201-011=
+1-
+22=21
+121-=02=1--222
+2=-=2
+1--1=-2-002-=-21
+1=-=1=1-==0=-
+1-==01000-1-121
+1=0=1==00=1-
+2110-1-21201002-0=1
+1--=11
+2=0-0-2=20020=1=1
+1-0=2-=12020111-1222
+101-=0--=1=00101
+2-=022-0-22=12=-0
+2=-1201-20==-2=20
+1-=21001
+1==2210220
+1=-21--1-
+1--==0212-10021-=1
+10-
+102011-0=2=
+22-100=---0-0
+1-0222--0-220--
+10211
+1-2--=10=-1-
+1-20-111
+1-1202=1=021
+2==0==0-0=2
+2=210=01--=011-
+21-
+1=02-210-0
+11
+1-0-21===0-=1-=2-
+10=22012=2-0-12-
+112
+21-1-22
+1=0010021=01
+2-0=120
+1=0-0-2-0-=
+212=20--
+1-=1--21-=
+1--
+2-12---=1202-1
+2=1
+1-0-11=021
+2-0-120-
+1-=10102-0-11201121
+1021---
+1=02=0012=-00=211
+10-1=2-0=-1-=
+11-1=0==1
+1=-1--12222
+1=00-0
+1--211
+1=10-=2=22--==-
+1=0=12--212=--=-1
+10200
+100=22=020210=12=-
+2-1=0=221
+1-02-0=
+2-1-20
+220=20
+22=202
+1==11=-11
+21=21=10=2=2=
+10100=-1===--2--=-
+1=-012=1
+210==0=-0-2120
+1002220--00=22
+1-2
+202-=1221-=----1
+202-0201122-2
+10010-02=02-1
+11=02-0--2=-10
+1==2-22--=1=-12=--
+12000
+1===1--=2-2=2----==
+10-12=
+1=1--=2==12
+1-2=0=12=0
+1=-1
+1=2-=0=020=-00=
+1-0-211-
+12-=1=01=0=22-2==2
+2=2=0-02-2
+212022
+101=11=
+1=00-2==0201==1
+2=-011=212221=212
+2-2
+1=-20-=--101
+1-212=12=0-0==1-
+2--2-1-0-11-2
+20-
+11-----0-
+102--=1011=01
+1--11--
+1-2=1=1==20111
+21200-===20
+1-0=12-0=
+2---
+20-2=
+1=-
+221-==
+1-01212==01-1220
+1-01202=10--010001
diff --git a/day25/input.test b/day25/input.test
new file mode 100644
index 0000000..237ef0c
--- /dev/null
+++ b/day25/input.test
@@ -0,0 +1,13 @@
+1=-0-2
+12111
+2=0=
+21
+2=01
+111
+20012
+112
+1=-1=
+1-12
+12
+1=
+122
\ No newline at end of file
diff --git a/day25/src/main.rs b/day25/src/main.rs
new file mode 100644
index 0000000..bb4b22e
--- /dev/null
+++ b/day25/src/main.rs
@@ -0,0 +1,165 @@
+use std::{
+    convert::Infallible,
+    fmt::Display,
+    fs::File,
+    io::{BufRead, BufReader},
+    ops::Add,
+    str::FromStr,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+struct Snafu(isize);
+
+fn solve<R: BufRead>(reader: R) -> Snafu {
+    reader
+        .lines()
+        .map(Result::unwrap)
+        .map(|line| line.parse::<Snafu>())
+        .map(Result::unwrap)
+        .sum()
+}
+
+fn main() {
+    let mut args = ::std::env::args().skip(1);
+    let file = args.next().unwrap_or_else(|| String::from("./input"));
+    let file = BufReader::new(File::open(file).expect("Opening file"));
+    println!("{}", solve(file))
+}
+
+impl FromStr for Snafu {
+    type Err = Infallible;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let dec = s
+            .as_bytes()
+            .iter()
+            .rev()
+            .map(|&byte| match byte {
+                b'=' => -2_isize,
+                b'-' => -1,
+                b'0' => 0,
+                b'1' => 1,
+                b'2' => 2,
+                _ => unreachable!(),
+            })
+            .scan(0_u32, |power, number| {
+                let base5 = number * 5_isize.pow(*power);
+                *power += 1;
+                Some(base5)
+            })
+            .sum();
+        Ok(Self(dec))
+    }
+}
+
+impl PartialEq<isize> for Snafu {
+    fn eq(&self, other: &isize) -> bool {
+        self.0.eq(other)
+    }
+}
+
+impl From<isize> for Snafu {
+    fn from(raw: isize) -> Self {
+        Snafu(raw)
+    }
+}
+
+impl Display for Snafu {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut target = self.0;
+        let mut power = (target.abs() * 2).ilog(5);
+        loop {
+            let five_pow = 5_isize.pow(power);
+            // The digit can be found by checking into which interval the target value falls
+            // [(x - 0.5) * 5^p, .., (x + 0.5) * 5^p] where x in [-2, .., 2]
+            let digit = (-2..=2)
+                .find(|&x| {
+                    // Double everything to get rid of the floats
+                    let from = (2 * x - 1) * five_pow;
+                    let to = (2 * x + 1) * five_pow;
+                    (from..to).contains(&(2 * target))
+                })
+                .unwrap();
+            write!(
+                f,
+                "{}",
+                match digit {
+                    -2 => "=",
+                    -1 => "-",
+                    0 => "0",
+                    1 => "1",
+                    2 => "2",
+                    digit => unreachable!("What, why {digit}"),
+                }
+            )?;
+            target -= digit * five_pow;
+            if power == 0 {
+                break Ok(());
+            }
+            power -= 1;
+        }
+    }
+}
+
+impl Add for Snafu {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Self::Output {
+        Self(self.0 + rhs.0)
+    }
+}
+
+impl std::iter::Sum for Snafu {
+    fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
+        iter.fold(Snafu::from(0), |acc, snafu| acc + snafu)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::Cursor;
+
+    use super::*;
+
+    #[test]
+    fn example() {
+        let reader = Cursor::new(include_str!("../input.test"));
+        assert_eq!(solve(reader).to_string(), "2=-1=0");
+    }
+
+    #[test]
+    fn snafu_parsing() {
+        assert_eq!(Snafu::from_str("1=-0-2").unwrap(), 1747);
+        assert_eq!(Snafu::from_str("12111").unwrap(), 906);
+        assert_eq!(Snafu::from_str("2=0=").unwrap(), 198);
+        assert_eq!(Snafu::from_str("21").unwrap(), 11);
+        assert_eq!(Snafu::from_str("2=01").unwrap(), 201);
+        assert_eq!(Snafu::from_str("111").unwrap(), 31);
+        assert_eq!(Snafu::from_str("20012").unwrap(), 1257);
+        assert_eq!(Snafu::from_str("112").unwrap(), 32);
+        assert_eq!(Snafu::from_str("1=-1=").unwrap(), 353);
+        assert_eq!(Snafu::from_str("1-12").unwrap(), 107);
+        assert_eq!(Snafu::from_str("12").unwrap(), 7);
+        assert_eq!(Snafu::from_str("1=").unwrap(), 3);
+        assert_eq!(Snafu::from_str("122").unwrap(), 37);
+    }
+
+    #[test]
+    fn snafu_formatting() {
+        assert_eq!(Snafu::from(1).to_string(), "1");
+        assert_eq!(Snafu::from(2).to_string(), "2");
+        assert_eq!(Snafu::from(3).to_string(), "1=");
+        assert_eq!(Snafu::from(4).to_string(), "1-");
+        assert_eq!(Snafu::from(5).to_string(), "10");
+        assert_eq!(Snafu::from(6).to_string(), "11");
+        assert_eq!(Snafu::from(7).to_string(), "12");
+        assert_eq!(Snafu::from(8).to_string(), "2=");
+        assert_eq!(Snafu::from(9).to_string(), "2-");
+        assert_eq!(Snafu::from(10).to_string(), "20");
+        assert_eq!(Snafu::from(15).to_string(), "1=0");
+        assert_eq!(Snafu::from(20).to_string(), "1-0");
+        assert_eq!(Snafu::from(2022).to_string(), "1=11-2");
+        assert_eq!(Snafu::from(12345).to_string(), "1-0---0");
+        assert_eq!(Snafu::from(314159265).to_string(), "1121-1110-1=0");
+    }
+}