Day 24 part 2.

Day 24 part 1.
intermediate
2023-11-14 19:35:00 +01:00 · 2023-11-14 18:48:45 +01:00 · 2023-11-14 16:56:16 +01:00 · 2023-11-14 16:41:54 +01:00 · 2023-11-13 23:22:51 +01:00 · 2023-11-13 19:52:52 +01:00
12 changed files with 5784 additions and 141 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,13 +4,28 @@ version = 3

 [[package]]
 name = "aho-corasick"
-version = "0.6.9"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e9a933f4e58658d7b12defcf96dc5c720f20832deebe3e0a19efd3b6aaeeb9e"
+checksum = "b2969dcb958b36655471fc61f7e416fa76033bdd4bfed0678d8fee1e2d07a1f0"
 dependencies = [
 "memchr",
 ]

+[[package]]
+name = "android-tzdata"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999941b234f3131b00bc13c22d06e8c5ff726d1b6318ac7eb276997bbb4fef0"
+
+[[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "aoc_2018"
 version = "0.1.0"
@@ -32,6 +47,12 @@ dependencies = [
 "byteorder",
 ]

+[[package]]
+name = "bumpalo"
+version = "3.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f30e7476521f6f8af1a1c4c0b8cc94f0bee37d91763d0ca2665f299b6cd8aec"
+
 [[package]]
 name = "byteorder"
 version = "1.4.3"
@@ -39,22 +60,40 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"

 [[package]]
-name = "cfg-if"
-version = "0.1.6"
+name = "cc"
+version = "1.0.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "082bb9b28e00d3c9d39cc03e64ce4cea0f1bb9b3fde493f0cbc008472d22bdf4"
+checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

 [[package]]
 name = "chrono"
-version = "0.4.6"
+version = "0.4.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
+checksum = "7f2c685bad3eb3d45a01354cedb7d5faa66194d1d58ba6e267a8de788f79db38"
 dependencies = [
- "num-integer",
+ "android-tzdata",
+ "iana-time-zone",
+ "js-sys",
 "num-traits",
- "time",
+ "wasm-bindgen",
+ "windows-targets",
 ]

+[[package]]
+name = "core-foundation-sys"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
+
 [[package]]
 name = "either"
 version = "1.5.0"
@@ -68,45 +107,69 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0896cb73353671dbe2b17312c97b55b7032831d28c809c703bece4a392b1df3a"

 [[package]]
-name = "itertools"
-version = "0.7.11"
+name = "iana-time-zone"
+version = "0.1.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d47946d458e94a1b7bcabbf6521ea7c037062c81f534615abcad76e84d4970d"
+checksum = "8326b86b6cff230b97d0d312a6c40a60726df3332e721f72a1b035f451663b20"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "itertools"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
 dependencies = [
 "either",
 ]

 [[package]]
-name = "lazy_static"
-version = "1.2.0"
+name = "js-sys"
+version = "0.3.65"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"
+checksum = "54c0c35952f67de54bb584e9fd912b3023117cbafc0a77d8f3dee1fb5f572fe8"
+dependencies = [
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
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 [[package]]
 name = "libc"
-version = "0.2.44"
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-checksum = "10923947f84a519a45c8fefb7dd1b3e8c08747993381adee176d7a82b4195311"
+checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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 [[package]]
 name = "memchr"
-version = "2.1.1"
+version = "2.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a3eb002f0535929f1199681417029ebea04aadc0c7a4224b46be99c7f5d6a16"
-dependencies = [
- "cfg-if",
- "libc",
- "version_check",
-]
-
-[[package]]
-name = "num-integer"
-version = "0.1.39"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e83d528d2677f0518c570baf2b7abdcf0cd2d248860b68507bdcb3e91d4c0cea"
-dependencies = [
- "num-traits",
-]
+checksum = "f665ee40bc4a3c5590afb1e9677db74a508659dfd71e126420da8274909a0167"

 [[package]]
 name = "num-traits"
@@ -115,89 +178,191 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"

 [[package]]
-name = "redox_syscall"
-version = "0.1.43"
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 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "679da7508e9a6390aeaf7fbd02a800fdc64b73fe2204dd2c8ae66d22d9d5ad5d"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+
+[[package]]
+name = "proc-macro2"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "134c189feb4956b20f6f547d2cf727d4c0fe06722b20a0eec87ed445a97f92da"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+dependencies = [
+ "proc-macro2",
+]

 [[package]]
 name = "regex"
-version = "1.1.0"
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+checksum = "380b951a9c5e80ddfd6136919eef32310721aa4aacd4889a8d39124b026ab343"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f804c7828047e88b2d32e2d7fe5a105da8ee3264f01902f796c8e067dc2483f"
 dependencies = [
 "aho-corasick",
 "memchr",
 "regex-syntax",
- "thread_local",
- "utf8-ranges",
 ]

 [[package]]
 name = "regex-syntax"
-version = "0.6.4"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e47a2ed29da7a9e1960e1639e7a982e6edc6d49be308a3b02daf511504a16d1"
+checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"
+
+[[package]]
+name = "syn"
+version = "2.0.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23e78b90f2fcf45d3e842032ce32e3f2d1545ba6636271dcbf24fa306d87be7a"
 dependencies = [
- "ucd-util",
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
 ]

 [[package]]
-name = "thread_local"
-version = "0.3.6"
+name = "unicode-ident"
+version = "1.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.88"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7daec296f25a1bae309c0cd5c29c4b260e510e6d813c286b19eaadf409d40fce"
 dependencies = [
- "lazy_static",
+ "cfg-if",
+ "wasm-bindgen-macro",
 ]

 [[package]]
-name = "time"
-version = "0.1.40"
+name = "wasm-bindgen-backend"
+version = "0.2.88"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d825be0eb33fda1a7e68012d51e9c7f451dc1a69391e7fdc197060bb8c56667b"
+checksum = "e397f4664c0e4e428e8313a469aaa58310d302159845980fd23b0f22a847f217"
 dependencies = [
- "libc",
- "redox_syscall",
- "winapi",
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
 ]

 [[package]]
-name = "ucd-util"
-version = "0.1.3"
+name = "wasm-bindgen-macro"
+version = "0.2.88"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
-
-[[package]]
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-
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-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
-
-[[package]]
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+checksum = "5961017b3b08ad5f3fe39f1e79877f8ee7c23c5e5fd5eb80de95abc41f1f16b2"
 dependencies = [
- "winapi-i686-pc-windows-gnu",
- "winapi-x86_64-pc-windows-gnu",
+ "quote",
+ "wasm-bindgen-macro-support",
 ]

 [[package]]
-name = "winapi-i686-pc-windows-gnu"
-version = "0.4.0"
+name = "wasm-bindgen-macro-support"
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 source = "registry+https://github.com/rust-lang/crates.io-index"
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+checksum = "c5353b8dab669f5e10f5bd76df26a9360c748f054f862ff5f3f8aae0c7fb3907"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]

 [[package]]
-name = "winapi-x86_64-pc-windows-gnu"
-version = "0.4.0"
+name = "wasm-bindgen-shared"
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-checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+checksum = "0d046c5d029ba91a1ed14da14dca44b68bf2f124cfbaf741c54151fdb3e0750b"
+
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+checksum = "f1f8cf84f35d2db49a46868f947758c7a1138116f7fac3bc844f43ade1292e64"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
+[[package]]
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+version = "0.48.5"
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+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
+[[package]]
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+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,9 +5,9 @@ authors = ["Johannes <jschaef@mail.uni-paderborn.de>"]
 edition = "2021"

 [dependencies]
-regex = "1.1.0"
-chrono = "0.4.6"
-itertools = "0.7.11"
+regex = "1.10.2"
+chrono = "0.4.31"
+itertools = "0.11.0"
 gcd = "1.1.0"
-lazy_static = "1.2.0"
+lazy_static = "1.4.0"
 bmp = "0.5.0"
--- a/input/day16.txt
+++ b/input/day16.txt
--- a/input/day19.txt
+++ b/input/day19.txt
@@ -0,0 +1,37 @@
+#ip 4
+addi 4 16 4
+seti 1 9 5
+seti 1 5 2
+mulr 5 2 1
+eqrr 1 3 1
+addr 1 4 4
+addi 4 1 4
+addr 5 0 0
+addi 2 1 2
+gtrr 2 3 1
+addr 4 1 4
+seti 2 6 4
+addi 5 1 5
+gtrr 5 3 1
+addr 1 4 4
+seti 1 2 4
+mulr 4 4 4
+addi 3 2 3
+mulr 3 3 3
+mulr 4 3 3
+muli 3 11 3
+addi 1 5 1
+mulr 1 4 1
+addi 1 2 1
+addr 3 1 3
+addr 4 0 4
+seti 0 2 4
+setr 4 8 1
+mulr 1 4 1
+addr 4 1 1
+mulr 4 1 1
+muli 1 14 1
+mulr 1 4 1
+addr 3 1 3
+seti 0 0 0
+seti 0 2 4
--- a/input/day21.txt
+++ b/input/day21.txt
@@ -0,0 +1,32 @@
+#ip 1
+seti 123 0 2
+bani 2 456 2
+eqri 2 72 2
+addr 2 1 1
+seti 0 0 1
+seti 0 3 2
+bori 2 65536 5
+seti 4843319 1 2
+bani 5 255 4
+addr 2 4 2
+bani 2 16777215 2
+muli 2 65899 2
+bani 2 16777215 2
+gtir 256 5 4
+addr 4 1 1
+addi 1 1 1
+seti 27 4 1
+seti 0 7 4
+addi 4 1 3
+muli 3 256 3
+gtrr 3 5 3
+addr 3 1 1
+addi 1 1 1
+seti 25 0 1
+addi 4 1 4
+seti 17 0 1
+setr 4 1 5
+seti 7 3 1
+eqrr 2 0 4
+addr 4 1 1
+seti 5 3 1
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,3 @@
 fn main() {
-    aoc_2018::tasks::day25::task1();
+    aoc_2018::tasks::day24::task2();
 }
--- a/src/tasks/day16.rs
+++ b/src/tasks/day16.rs
@@ -0,0 +1,630 @@
+use std::collections::{HashMap, HashSet};
+use std::ops::{BitAnd, BitOr};
+
+use itertools::Itertools;
+
+pub fn task1() {
+    let count = include_str!("../../input/day16.txt")
+        .split_once("\n\n\n\n")
+        .unwrap()
+        .0
+        .split("\n\n")
+        .map(|sample_input| parse(sample_input))
+        .map(matches_count)
+        .filter(|count| *count >= 3)
+        .count();
+    println!("Day 16 part1: {count}");
+}
+
+pub fn task2() {
+    let (samples, program) = include_str!("../../input/day16.txt")
+        .split_once("\n\n\n\n")
+        .unwrap();
+
+    let code_to_op_candidates = samples
+        .split("\n\n")
+        .map(|sample_input| parse(sample_input))
+        .map(|sample| (sample.1.opcode, matches_ops(sample)))
+        .into_group_map_by(|x| x.0);
+
+    // let code_to_op: HashMap<usize, HashSet<Op>> =
+    let mut code_to_op_candidates: HashMap<_, _> = code_to_op_candidates
+        .into_iter()
+        .map(|(code, ops)| {
+            let mut set: HashSet<_> = HashSet::from_iter(OPS.iter().map(ToOwned::to_owned));
+            for (_, candidate_set) in ops {
+                set = set
+                    .intersection(&candidate_set)
+                    .map(ToOwned::to_owned)
+                    .collect();
+            }
+
+            (code, set)
+        })
+        .collect();
+
+    let mut codes_to_op: HashMap<usize, Op> = HashMap::new();
+    loop {
+        let single = code_to_op_candidates.iter().find(|(_, ops)| ops.len() == 1);
+        let Some(single) = single else {
+            break;
+        };
+
+        let code = *single.0;
+        let op = *single.1.iter().next().unwrap();
+
+        codes_to_op.insert(code, op);
+
+        code_to_op_candidates.iter_mut().for_each(|(_, ops)| {
+            ops.remove(&op);
+        });
+    }
+
+    if codes_to_op.len() != OPS.len() {
+        panic!("Bad final opcode assignments: {codes_to_op:?}");
+    }
+
+    let program: Vec<Instruction> = program.lines().map(parse_instruction).collect();
+
+    let mut registers = Registers([0, 0, 0, 0]);
+    for instruction in program {
+        let op: Op = codes_to_op[&instruction.opcode];
+        registers = op.process(registers, instruction);
+    }
+
+    println!("Day 16 part 2: {}", registers.0[0]);
+}
+
+fn parse(sample: &str) -> Sample {
+    let (before, instruction, after) = sample.lines().collect_tuple().unwrap();
+    let before: Vec<_> = before
+        .trim_start_matches("Before: [")
+        .trim_end_matches("]")
+        .split(", ")
+        .collect();
+    let before = Registers::from(before);
+    let after: Vec<_> = after
+        .trim_start_matches("After:  [")
+        .trim_end_matches("]")
+        .split(", ")
+        .collect();
+    let after = Registers::from(after);
+    let instruction = parse_instruction(instruction);
+
+    Sample(before, instruction, after)
+}
+
+fn parse_instruction(instruction: &str) -> Instruction {
+    let instruction: Vec<usize> = instruction.split(" ").map(|x| x.parse().unwrap()).collect();
+    let instruction = Instruction {
+        opcode: instruction[0],
+        a: instruction[1],
+        b: instruction[2],
+        c: instruction[3],
+    };
+    instruction
+}
+
+fn matches(sample: Sample, op: Op) -> bool {
+    op.process(sample.0, sample.1) == sample.2
+}
+
+fn matches_count(sample: Sample) -> usize {
+    let vec = OPS.iter().filter(|op| matches(sample, **op)).collect_vec();
+    vec.len()
+}
+
+fn matches_ops(sample: Sample) -> HashSet<Op> {
+    OPS.iter()
+        .filter(|op| matches(sample, **op))
+        .map(|op| op.to_owned())
+        .collect()
+}
+
+const OPS: &[Op] = &[
+    Op::AddR,
+    Op::AddI,
+    Op::MulR,
+    Op::MulI,
+    Op::BanR,
+    Op::BanI,
+    Op::BorR,
+    Op::BorI,
+    Op::SetR,
+    Op::SetI,
+    Op::GtIR,
+    Op::GtRI,
+    Op::GtRR,
+    Op::EqIR,
+    Op::EqRI,
+    Op::EqRR,
+];
+
+#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
+enum Op {
+    AddR,
+    AddI,
+    MulR,
+    MulI,
+    BanR,
+    BanI,
+    BorR,
+    BorI,
+    SetR,
+    SetI,
+    GtIR,
+    GtRI,
+    GtRR,
+    EqIR,
+    EqRI,
+    EqRR,
+}
+
+impl Op {
+    fn process(&self, registers: Registers, instruction: Instruction) -> Registers {
+        let mut result = registers.0.clone();
+
+        match self {
+            Op::AddR => {
+                result[instruction.c] = result[instruction.a] + result[instruction.b];
+            }
+            Op::AddI => {
+                result[instruction.c] = result[instruction.a] + instruction.b as i32;
+            }
+            Op::MulR => {
+                result[instruction.c] = result[instruction.a] * result[instruction.b];
+            }
+            Op::MulI => {
+                result[instruction.c] = result[instruction.a] * instruction.b as i32;
+            }
+            Op::BanR => {
+                result[instruction.c] = result[instruction.a].bitand(result[instruction.b]);
+            }
+            Op::BanI => {
+                result[instruction.c] = result[instruction.a].bitand(instruction.b as i32);
+            }
+            Op::BorR => {
+                result[instruction.c] = result[instruction.a].bitor(result[instruction.b]);
+            }
+            Op::BorI => {
+                result[instruction.c] = result[instruction.a].bitor(instruction.b as i32);
+            }
+            Op::SetR => {
+                result[instruction.c] = result[instruction.a];
+            }
+            Op::SetI => {
+                result[instruction.c] = instruction.a as i32;
+            }
+            Op::GtIR => {
+                result[instruction.c] = if instruction.a as i32 > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRI => {
+                result[instruction.c] = if result[instruction.a] > instruction.b as i32 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRR => {
+                result[instruction.c] = if result[instruction.a] > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqIR => {
+                result[instruction.c] = if instruction.a as i32 == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRI => {
+                result[instruction.c] = if result[instruction.a] == instruction.b as i32 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRR => {
+                result[instruction.c] = if result[instruction.a] == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+        }
+
+        Registers(result)
+    }
+}
+
+#[derive(Copy, Clone)]
+struct Sample(Registers, Instruction, Registers);
+
+#[derive(Eq, PartialEq, Copy, Clone, Debug)]
+struct Registers([i32; 4]);
+
+impl From<Vec<&str>> for Registers {
+    fn from(value: Vec<&str>) -> Self {
+        let values: Vec<_> = value.iter().map(|x| x.parse().unwrap()).collect();
+        Registers([values[0], values[1], values[2], values[3]])
+    }
+}
+
+#[derive(Copy, Clone)]
+struct Instruction {
+    opcode: usize,
+    a: usize,
+    b: usize,
+    c: usize,
+}
+
+#[cfg(test)]
+mod test {
+    use crate::tasks::day16::{matches_count, parse, Instruction, Op, Registers};
+
+    #[test]
+    fn example1() {
+        let input = "Before: [3, 2, 1, 1]\n\
+                          9 2 1 2\n\
+                          After:  [3, 2, 2, 1]";
+        assert_eq!(matches_count(parse(input)), 3);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_AddR() {
+        let op = Op::AddR;
+        let result = op.process(
+            Registers([3, 4, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(7, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_AddI() {
+        let op = Op::AddI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 1337,
+                c: 3,
+            },
+        );
+        assert_eq!(1338, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_MulR() {
+        let op = Op::MulR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 2,
+                c: 3,
+            },
+        );
+        assert_eq!(6, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_MulI() {
+        let op = Op::MulI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1337,
+                c: 3,
+            },
+        );
+        assert_eq!(2 * 1337, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_BanR() {
+        let op = Op::BanR;
+        let result = op.process(
+            Registers([0x10101, 0x10110, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0x10100, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_BanI() {
+        let op = Op::BanI;
+        let result = op.process(
+            Registers([0x10101, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 0x10110,
+                c: 3,
+            },
+        );
+        assert_eq!(0x10100, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_BorR() {
+        let op = Op::BorR;
+        let result = op.process(
+            Registers([0x10101, 0x10110, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0x10111, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_BorI() {
+        let op = Op::BorI;
+        let result = op.process(
+            Registers([0x10101, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 0,
+                b: 0x10110,
+                c: 3,
+            },
+        );
+        assert_eq!(0x10111, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_SetR() {
+        let op = Op::SetR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(2, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_SetI() {
+        let op = Op::SetI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1234,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(1234, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtIR_true() {
+        let op = Op::GtIR;
+        let result = op.process(
+            Registers([1, 29, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 30,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtIR_false() {
+        let op = Op::GtIR;
+        let result = op.process(
+            Registers([1, 1337, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1337,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtRI_true() {
+        let op = Op::GtRI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 2,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtRI_false() {
+        let op = Op::GtRI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 2,
+                b: 3,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtRR_true() {
+        let op = Op::GtRR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 0,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_GtRR() {
+        let op = Op::GtRR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqIR_true() {
+        let op = Op::EqIR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 0,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqIR_false() {
+        let op = Op::EqIR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqRI_true() {
+        let op = Op::EqRI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 2,
+                b: 3,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqRI_false() {
+        let op = Op::EqRI;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqRR_true() {
+        let op = Op::EqRR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 1,
+                c: 3,
+            },
+        );
+        assert_eq!(1, result.0[3]);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn test_EqRR_false() {
+        let op = Op::EqRR;
+        let result = op.process(
+            Registers([1, 2, 3, 4]),
+            Instruction {
+                opcode: 0,
+                a: 1,
+                b: 2,
+                c: 3,
+            },
+        );
+        assert_eq!(0, result.0[3]);
+    }
+}
--- a/src/tasks/day19.rs
+++ b/src/tasks/day19.rs
@@ -0,0 +1,243 @@
+use std::ops::{BitAnd, BitOr};
+
+pub fn task1() {
+    let input = include_str!("../../input/day19.txt");
+    let result = run1(input, 1);
+
+    println!("Day 19 part 1: {result}");
+}
+
+pub fn task2() {
+    let mut a = 1i64;
+    let mut d = 948;
+    if a == 1 {
+        d += 10550400;
+        a = 0;
+    }
+
+    let mut f = 1;
+    'outer: loop {
+        let mut c = 1;
+        'inner: loop {
+            let b = f * c;
+            if b == d {
+                a = a + f;
+            } else if b > d {
+                // this is the important part: break the loop because otherwise we count and count
+                // and count ... but cannot reach the b == d condition without resetting c.
+                break 'inner;
+            }
+            c += 1;
+            if c > d {
+                break 'inner;
+            }
+        }
+        f += 1;
+        if f > d {
+            break 'outer;
+        }
+    }
+
+    println!("Day 19 part 2: {a}");
+}
+
+fn run1(input: &str, start_value: i32) -> i32 {
+    let (config, program) = input.split_once("\n").unwrap();
+    let ip_register: usize = config.split_once(" ").unwrap().1.parse().unwrap();
+
+    let program: Vec<Instruction> = program.lines().map(parse_instruction).collect();
+
+    let mut registers: Registers = [start_value, 0, 0, 0, 0, 0];
+    let mut ip = 0;
+    let mut count = 0;
+    loop {
+        //print!("ip={ip}, {registers:?}");
+
+        registers[ip_register] = ip as i32;
+        let instruction = program.get(ip).unwrap();
+
+        if ip == 2 {
+            println!("{registers:?}");
+        }
+
+        //print!("{instruction:?}");
+
+        let op: Op = instruction.opcode;
+        registers = op.process(registers, *instruction);
+
+        //println!("{registers:?}");
+
+        ip = registers[ip_register] as usize;
+        ip += 1;
+
+        if program.get(ip).is_none() {
+            break;
+        }
+        count += 1;
+    }
+    println!("executed instructions: {count}");
+    registers[0]
+}
+
+fn parse_instruction(instruction: &str) -> Instruction {
+    let instruction: Vec<_> = instruction.split(" ").collect();
+    let opcode = match instruction[0] {
+        "addr" => Op::AddR,
+        "addi" => Op::AddI,
+        "mulr" => Op::MulR,
+        "muli" => Op::MulI,
+        "banr" => Op::BanR,
+        "bani" => Op::BanI,
+        "borr" => Op::BorR,
+        "bori" => Op::BorI,
+        "setr" => Op::SetR,
+        "seti" => Op::SetI,
+        "gtir" => Op::GtIR,
+        "gtri" => Op::GtRI,
+        "gtrr" => Op::GtRR,
+        "eqir" => Op::EqIR,
+        "eqri" => Op::EqRI,
+        "eqrr" => Op::EqRR,
+        &_ => {
+            panic!("unknown op {}", instruction[0])
+        }
+    };
+    let instruction = Instruction {
+        opcode,
+        a: instruction[1].parse().unwrap(),
+        b: instruction[2].parse().unwrap(),
+        c: instruction[3].parse().unwrap(),
+    };
+    instruction
+}
+
+#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
+enum Op {
+    AddR,
+    AddI,
+    MulR,
+    MulI,
+    BanR,
+    BanI,
+    BorR,
+    BorI,
+    SetR,
+    SetI,
+    GtIR,
+    GtRI,
+    GtRR,
+    EqIR,
+    EqRI,
+    EqRR,
+}
+
+impl Op {
+    fn process(&self, registers: Registers, instruction: Instruction) -> Registers {
+        let mut result = registers.clone();
+
+        match self {
+            Op::AddR => {
+                result[instruction.c] = result[instruction.a] + result[instruction.b];
+            }
+            Op::AddI => {
+                result[instruction.c] = result[instruction.a] + instruction.b as i32;
+            }
+            Op::MulR => {
+                result[instruction.c] = result[instruction.a] * result[instruction.b];
+            }
+            Op::MulI => {
+                result[instruction.c] = result[instruction.a] * instruction.b as i32;
+            }
+            Op::BanR => {
+                result[instruction.c] = result[instruction.a].bitand(result[instruction.b]);
+            }
+            Op::BanI => {
+                result[instruction.c] = result[instruction.a].bitand(instruction.b as i32);
+            }
+            Op::BorR => {
+                result[instruction.c] = result[instruction.a].bitor(result[instruction.b]);
+            }
+            Op::BorI => {
+                result[instruction.c] = result[instruction.a].bitor(instruction.b as i32);
+            }
+            Op::SetR => {
+                result[instruction.c] = result[instruction.a];
+            }
+            Op::SetI => {
+                result[instruction.c] = instruction.a as i32;
+            }
+            Op::GtIR => {
+                result[instruction.c] = if instruction.a as i32 > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRI => {
+                result[instruction.c] = if result[instruction.a] > instruction.b as i32 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRR => {
+                result[instruction.c] = if result[instruction.a] > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqIR => {
+                result[instruction.c] = if instruction.a as i32 == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRI => {
+                result[instruction.c] = if result[instruction.a] == instruction.b as i32 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRR => {
+                result[instruction.c] = if result[instruction.a] == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+        }
+
+        result
+    }
+}
+
+type Registers = [i32; 6];
+
+#[derive(Copy, Clone, Debug)]
+struct Instruction {
+    opcode: Op,
+    a: usize,
+    b: usize,
+    c: usize,
+}
+
+#[cfg(test)]
+mod test {
+    use crate::tasks::day19::run1;
+
+    #[test]
+    fn example1() {
+        let input = "#ip 0\n\
+                          seti 5 0 1\n\
+                          seti 6 0 2\n\
+                          addi 0 1 0\n\
+                          addr 1 2 3\n\
+                          setr 1 0 0\n\
+                          seti 8 0 4\n\
+                          seti 9 0 5";
+        assert_eq!(run1(input, 0), 6);
+    }
+}
--- a/src/tasks/day21.rs
+++ b/src/tasks/day21.rs
@@ -0,0 +1,229 @@
+use std::collections::HashSet;
+use std::ops::{BitAnd, BitOr};
+
+pub fn task1() {
+    let input = include_str!("../../input/day21.txt");
+    let result = run1(input, 3007673);
+    println!("{result:?}");
+}
+
+fn run1(input: &str, start_value: i64) -> (i64, usize) {
+    let (config, program) = input.split_once("\n").unwrap();
+    let ip_register: usize = config.split_once(" ").unwrap().1.parse().unwrap();
+
+    let program: Vec<Instruction> = program.lines().map(parse_instruction).collect();
+
+    let mut registers: Registers = [start_value, 0, 0, 0, 0, 0];
+    let mut ip = 0;
+    let mut count = 0usize;
+    let mut seen: HashSet<_> = HashSet::new();
+    let mut last = 0;
+    loop {
+        //print!("ip={ip}, {registers:?}");
+
+        registers[ip_register] = ip as i64;
+        let instruction = program.get(ip).unwrap();
+
+        //print!("{instruction:?}");
+
+        let op: Op = instruction.opcode;
+        registers = op.process(registers, *instruction);
+
+        //println!("{registers:?}");
+
+        ip = registers[ip_register] as usize;
+        ip += 1;
+
+        // Part 1: uncomment this and print look at register 2 to find the value for register 0
+        // that would cause the program to halt
+        // if ip == 28 {
+        //     println!("Value in register 2: {}", registers[2]);
+        // }
+        // Part 2:  9969507 too high
+        // 16774755 highest value
+        // Store all values of register 2 at the possible exit point. Once you see one you already
+        // saw: you've seen all (there is a loop). The one before that was the one it took the longest
+        // to reach without seeing anything twice.
+        if ip == 28 {
+            if seen.contains(&registers[2]) {
+                println!("First double: {registers:?}");
+                println!("Last was {last}");
+                break;
+            } else {
+                seen.insert(registers[2]);
+                last = registers[2];
+            }
+        }
+
+        if program.get(ip).is_none() {
+            println!("exit by leaving instruction space");
+            break;
+        }
+        count += 1;
+    }
+    println!("executed instructions: {count}");
+    (registers[0], count)
+}
+
+fn parse_instruction(instruction: &str) -> Instruction {
+    let instruction: Vec<_> = instruction.split(" ").collect();
+    let opcode = match instruction[0] {
+        "addr" => Op::AddR,
+        "addi" => Op::AddI,
+        "mulr" => Op::MulR,
+        "muli" => Op::MulI,
+        "banr" => Op::BanR,
+        "bani" => Op::BanI,
+        "borr" => Op::BorR,
+        "bori" => Op::BorI,
+        "setr" => Op::SetR,
+        "seti" => Op::SetI,
+        "gtir" => Op::GtIR,
+        "gtri" => Op::GtRI,
+        "gtrr" => Op::GtRR,
+        "eqir" => Op::EqIR,
+        "eqri" => Op::EqRI,
+        "eqrr" => Op::EqRR,
+        &_ => {
+            panic!("unknown op {}", instruction[0])
+        }
+    };
+    let instruction = Instruction {
+        opcode,
+        a: instruction[1].parse().unwrap(),
+        b: instruction[2].parse().unwrap(),
+        c: instruction[3].parse().unwrap(),
+    };
+    instruction
+}
+
+#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
+enum Op {
+    AddR,
+    AddI,
+    MulR,
+    MulI,
+    BanR,
+    BanI,
+    BorR,
+    BorI,
+    SetR,
+    SetI,
+    GtIR,
+    GtRI,
+    GtRR,
+    EqIR,
+    EqRI,
+    EqRR,
+}
+
+impl Op {
+    fn process(&self, registers: Registers, instruction: Instruction) -> Registers {
+        let mut result = registers.clone();
+
+        match self {
+            Op::AddR => {
+                result[instruction.c] = result[instruction.a] + result[instruction.b];
+            }
+            Op::AddI => {
+                result[instruction.c] = result[instruction.a] + instruction.b as i64;
+            }
+            Op::MulR => {
+                result[instruction.c] = result[instruction.a] * result[instruction.b];
+            }
+            Op::MulI => {
+                result[instruction.c] = result[instruction.a] * instruction.b as i64;
+            }
+            Op::BanR => {
+                result[instruction.c] = result[instruction.a].bitand(result[instruction.b]);
+            }
+            Op::BanI => {
+                result[instruction.c] = result[instruction.a].bitand(instruction.b as i64);
+            }
+            Op::BorR => {
+                result[instruction.c] = result[instruction.a].bitor(result[instruction.b]);
+            }
+            Op::BorI => {
+                result[instruction.c] = result[instruction.a].bitor(instruction.b as i64);
+            }
+            Op::SetR => {
+                result[instruction.c] = result[instruction.a];
+            }
+            Op::SetI => {
+                result[instruction.c] = instruction.a as i64;
+            }
+            Op::GtIR => {
+                result[instruction.c] = if instruction.a as i64 > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRI => {
+                result[instruction.c] = if result[instruction.a] > instruction.b as i64 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::GtRR => {
+                result[instruction.c] = if result[instruction.a] > result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqIR => {
+                result[instruction.c] = if instruction.a as i64 == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRI => {
+                result[instruction.c] = if result[instruction.a] == instruction.b as i64 {
+                    1
+                } else {
+                    0
+                }
+            }
+            Op::EqRR => {
+                result[instruction.c] = if result[instruction.a] == result[instruction.b] {
+                    1
+                } else {
+                    0
+                }
+            }
+        }
+
+        result
+    }
+}
+
+type Registers = [i64; 6];
+
+#[derive(Copy, Clone, Debug)]
+struct Instruction {
+    opcode: Op,
+    a: usize,
+    b: usize,
+    c: usize,
+}
+
+#[cfg(test)]
+mod test {
+    use crate::tasks::day21::run1;
+
+    #[test]
+    fn example1() {
+        let input = "#ip 0\n\
+                          seti 5 0 1\n\
+                          seti 6 0 2\n\
+                          addi 0 1 0\n\
+                          addr 1 2 3\n\
+                          setr 1 0 0\n\
+                          seti 8 0 4\n\
+                          seti 9 0 5";
+        assert_eq!(run1(input, 0).0, 6);
+    }
+}
--- a/src/tasks/day24.rs
+++ b/src/tasks/day24.rs
@@ -1,17 +1,32 @@
-use crate::utils;
 use std::cmp::Reverse;
 use std::collections::HashMap;

-pub fn task1() {
-    let _input = "Immune System:
-    17 units each with 5390 hit points (weak to radiation, bludgeoning) with an attack that does 4507 fire damage at initiative 2
-    989 units each with 1274 hit points (immune to fire; weak to bludgeoning, slashing) with an attack that does 25 slashing damage at initiative 3
+use itertools::Itertools;

-Infection:
-    801 units each with 4706 hit points (weak to radiation) with an attack that does 116 bludgeoning damage at initiative 1
-    4485 units each with 2961 hit points (immune to radiation; weak to fire, cold) with an attack that does 12 slashing damage at initiative 4";
+use crate::utils;
+
+pub fn task1() {
    let input = utils::read_file("input/day24.txt");
-    let mut game = Game::create(&input);
+
+    let result = play(&input, 0);
+    println!("Standing units after the game: {}", result.unwrap().1);
+}
+
+pub fn task2() {
+    let input = utils::read_file("input/day24.txt");
+
+    let immune_final_count = (0..)
+        .map(|boost| play(&input, boost))
+        .find(|result| result.map(|(team, _)| team) == Some(Team::ImmuneSystem))
+        .unwrap()
+        .unwrap()
+        .1;
+
+    println!("Immune systems final count: {immune_final_count}");
+}
+
+fn play(input: &str, boost: i64) -> Option<(Team, i64)> {
+    let mut game = Game::create(&input, boost);

    println!(
        "Immune start units: {}",
@@ -30,31 +45,41 @@ Infection:
            .sum::<i64>()
    );

-    let mut rounds_played = 0;
    while !game.is_over() {
        game.round();
-        rounds_played += 1;
+        if game.draw {
+            return None;
+        }
    }

-    println!("{:#?}", game);
-    println!("Played {} rounds", rounds_played);
-
-    println!(
-        "Standing units after the game: {}",
-        game.groups.values().map(|it| it.units).sum::<i64>()
-    );
-
-    // 21107 too high
-    // 21004 too high
+    Some((game.winning_team(), game.remaining_units()))
 }

 #[derive(Debug)]
 struct Game {
    groups: HashMap<usize, Group>,
+    draw: bool,
 }

 impl Game {
-    fn create(input: &str) -> Self {
+    fn remaining_units(&self) -> i64 {
+        self.groups.values().map(|it| it.units).sum::<i64>()
+    }
+
+    fn winning_team(&self) -> Team {
+        let teams: Vec<Team> = self
+            .groups
+            .values()
+            .map(|group| group.team)
+            .unique()
+            .collect();
+        if teams.len() != 1 {
+            panic!("No winning team. Remaining teams: {teams:?}");
+        }
+        teams[0]
+    }
+
+    fn create(input: &str, boost: i64) -> Self {
        let mut groups = HashMap::new();
        let mut team = Team::ImmuneSystem;
        for (id, line) in input.lines().enumerate() {
@@ -67,13 +92,21 @@ impl Game {
                }
                "" => (),
                group => {
-                    if let Some(group) = Group::from_str(group, team, id) {
+                    if let Some(mut group) = Group::from_str(group, team, id) {
+                        if group.team == Team::ImmuneSystem {
+                            group.attack_damage += boost;
+                        }
                        groups.insert(id, group);
+                    } else {
+                        panic!("bad group: {group}");
                    }
                }
            }
        }
-        Game { groups }
+        Game {
+            groups,
+            draw: false,
+        }
    }

    fn round(&mut self) {
@@ -96,7 +129,6 @@ impl Game {
                .values()
                .filter(|it| it.team != group.team)
                .filter(|it| !target.values().any(|t| *t == it.id))
-                // .filter(|it| group.compute_attack_damage_to(&it) >= it.hp_each)
                // .inspect(|it| {
                //     println!(
                //         "{} would deal {} damage to {}",
@@ -114,10 +146,10 @@ impl Game {
                })
            {
                if group.compute_attack_damage_to(t) <= 0 {
-                    println!(
-                        "Didn't find a target where {:?} can deal positive damage.",
-                        group
-                    );
+                    // println!(
+                    //     "Didn't find a target where {:?} can deal positive damage.",
+                    //     group
+                    // );
                    continue;
                } else {
                    target.insert(group.id, t.id);
@@ -129,18 +161,21 @@ impl Game {
        let mut all_ids_by_initiative: Vec<usize> = self.groups.values().map(|it| it.id).collect();
        all_ids_by_initiative.sort_unstable_by_key(|id| Reverse(self.groups[id].initiative));

+        self.draw = true;
        for active_id in all_ids_by_initiative {
            if !self.groups[&active_id].alive() {
                // was killed in this round
-                println!("Group {} already dead", active_id);
+                // println!("Group {} already dead", active_id);
                continue;
            }
            if let Some(enemy_id) = target.get(&active_id) {
                let enemy = &self.groups[enemy_id];
                let damage: i64 = self.groups[&active_id].compute_attack_damage_to(enemy);
                let dying_units = damage / enemy.hp_each;
-                if let Some(enemy) = self.groups.get_mut(enemy_id) {
-                    enemy.units -= dying_units;
+                self.groups.get_mut(enemy_id).unwrap().units -= dying_units;
+
+                if dying_units > 0 {
+                    self.draw = false;
                }
                // println!(
                //     "{} dealt {} ({} units) damage to {}",
@@ -155,8 +190,7 @@ impl Game {
    }

    fn is_over(&self) -> bool {
-        self.groups.is_empty()
-            || self.groups.iter().all(|(_, it)| it.team == Team::Infection)
+        self.groups.iter().all(|(_, it)| it.team == Team::Infection)
            || self
                .groups
                .iter()
@@ -164,7 +198,7 @@ impl Game {
    }
 }

-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 enum Team {
    Infection,
    ImmuneSystem,
@@ -186,8 +220,9 @@ struct Group {
 impl Group {
    fn from_str(input: &str, team: Team, id: usize) -> Option<Self> {
        // 801 units each with 4706 hit points (weak to radiation) with an attack that does 116 bludgeoning damage at initiative 1
+        // 2347 units each with 3322 hit points with an attack that does 12 cold damage at initiative 2
        use regex::Regex;
-        let regex = Regex::new(r"(\d+) units each with (\d+) hit points \((.+)\) with an attack that does (\d+) (\w+) damage at initiative (\d+)").unwrap();
+        let regex = Regex::new(r"(\d+) units each with (\d+) hit points(.*)with an attack that does (\d+) (\w+) damage at initiative (\d+)").unwrap();
        if let Some(m) = regex.captures(input) {
            let units: i64 = m[1].parse().unwrap();
            let hp_each: i64 = m[2].parse().unwrap();
@@ -196,7 +231,8 @@ impl Group {
            let initiative: u64 = m[6].parse().unwrap();
            let mut weaknesses: Vec<String> = Vec::new();
            let mut immunities: Vec<String> = Vec::new();
-            for part in m[3].split("; ") {
+            let attributes = m[3].trim().trim_start_matches("(").trim_end_matches(")");
+            for part in attributes.split("; ") {
                if let Some(stripped) = part.strip_prefix("weak to ") {
                    weaknesses = stripped.split(", ").map(|it| it.to_string()).collect();
                } else if let Some(stripped) = part.strip_prefix("immune to ") {
@@ -246,3 +282,26 @@ impl Group {
        }
    }
 }
+
+#[cfg(test)]
+mod test {
+    use crate::tasks::day24::play;
+
+    const INPUT: &str = "Immune System:
+    17 units each with 5390 hit points (weak to radiation, bludgeoning) with an attack that does 4507 fire damage at initiative 2
+    989 units each with 1274 hit points (immune to fire; weak to bludgeoning, slashing) with an attack that does 25 slashing damage at initiative 3
+
+Infection:
+    801 units each with 4706 hit points (weak to radiation) with an attack that does 116 bludgeoning damage at initiative 1
+    4485 units each with 2961 hit points (immune to radiation; weak to fire, cold) with an attack that does 12 slashing damage at initiative 4";
+
+    #[test]
+    fn example1() {
+        assert_eq!(5216, play(INPUT, 0).unwrap().1);
+    }
+
+    #[test]
+    fn example2() {
+        assert_eq!(51, play(INPUT, 1570).unwrap().1);
+    }
+}
--- a/src/tasks/day25.rs
+++ b/src/tasks/day25.rs
@@ -31,23 +31,6 @@ struct STP(i32, i32, i32, i32);
 impl STP {}

 impl STP {
-    fn neighbors(&self) -> Vec<Self> {
-        let mut result = Vec::new();
-        for x in -3..=3 {
-            for y in -3..=3 {
-                for z in -3..=3 {
-                    for t in -3..=3 {
-                        let candidate = STP(self.0 + x, self.1 + y, self.2 + z, self.3 + t);
-                        if self.is_neighbor_to(&candidate) {
-                            result.push(candidate);
-                        }
-                    }
-                }
-            }
-        }
-        result
-    }
-
    fn distance(&self, other: &Self) -> u32 {
        ((self.0 - other.0).abs()
            + (self.1 - other.1).abs()
@@ -73,6 +56,7 @@ impl From<&str> for STP {
    }
 }

+#[cfg(test)]
 mod test {
    use crate::tasks::day25::solve;

--- a/src/tasks/mod.rs
+++ b/src/tasks/mod.rs
@@ -13,9 +13,12 @@ pub mod day12;
 pub mod day13;
 pub mod day14;
 pub mod day15;
+pub mod day16;
 pub mod day17;
 pub mod day18;
+pub mod day19;
 pub mod day20;
+pub mod day21;
 pub mod day22;
 pub mod day23;
 pub mod day24;
Author	SHA1	Message	Date
Johannes	fc803d8a0f	Day 24 part 2.	2023-11-14 19:35:00 +01:00
Johannes	3a9379f877	Day 24 part 1.	2023-11-14 18:48:45 +01:00
Johannes	241c417a77	intermediate	2023-11-14 16:56:16 +01:00
Johannes	4cbe831115	Removed warnings.	2023-11-14 16:41:54 +01:00
Johannes	a4c33ae3d2	Day 21 part 2. Shitty bitty.	2023-11-13 23:22:51 +01:00
Johannes	48ad7e7a96	Day 21 part 1.	2023-11-13 19:52:52 +01:00
Johannes	caf307bf2d	Day 19 part 2 (manually reverse engineered the assembler instructions).	2023-11-12 23:12:46 +01:00
Johannes	2792304040	Day 19 part 1.	2023-11-12 21:25:31 +01:00
Johannes	42ead11aa0	Day 16 part 2.	2023-11-12 19:15:31 +01:00
Johannes	8e1f42205c	Day 16 part 1.	2023-11-12 16:14:45 +01:00
Johannes	c4ae25d579	Updated dependencies.	2023-11-12 12:36:02 +01:00