Add day11

day11/Cargo.lock

@@ -0,0 +1,119 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "ahash"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e89da841a80418a9b391ebaea17f5c112ffaaa96f621d2c285b5174da76b9011"
+dependencies = [
+ "cfg-if",
+ "getrandom",
+ "once_cell",
+ "version_check",
+ "zerocopy",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "day11"
+version = "0.1.0"
+dependencies = [
+ "ahash",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.168"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aaeb2981e0606ca11d79718f8bb01164f1d6ed75080182d3abf017e6d244b6d"
+
+[[package]]
+name = "once_cell"
+version = "1.20.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.90"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "919d3b74a5dd0ccd15aeb8f93e7006bd9e14c295087c9896a110f490752bcf31"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"
+
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
+[[package]]
+name = "zerocopy"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]

day11/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "day11"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+ahash = "0.8.11"

day11/src/main.rs

@@ -0,0 +1,54 @@
+use ahash::AHashMap;
+
+fn parse(input: &str) -> Vec<usize> {
+    input
+        .split_whitespace()
+        .map(|n| n.parse().unwrap())
+        .collect()
+}
+
+fn split_number(num: &usize) -> (usize, usize) {
+    let mut digit_count = 0;
+    let mut rest = *num;
+    while rest > 0 {
+        rest /= 10;
+        digit_count += 1;
+    }
+    let divisor = 10usize.pow(digit_count / 2);
+    (num % divisor, num / divisor)
+}
+
+fn get_amount(num: &usize, steps: &usize, cache: &mut AHashMap<(usize, usize), usize>) -> usize {
+    if let Some(val) = cache.get(&(*num, *steps)) {
+        return *val;
+    }
+    if steps == &0 {
+        return 1;
+    }
+    let mut res = 0;
+    if num == &0 {
+        res += get_amount(&1, &(steps - 1), cache);
+    } else if num.to_string().chars().count() % 2 == 0 {
+        let (splitl, splitr) = split_number(num);
+        res += get_amount(&splitl, &(steps - 1), cache);
+        res += get_amount(&splitr, &(steps - 1), cache);
+    } else {
+        res += get_amount(&(num * 2024), &(steps - 1), cache);
+    }
+    cache.insert((*num, *steps), res);
+    res
+}
+
+fn part(input: &[usize], steps: usize) -> usize {
+    let mut cache = AHashMap::new();
+    input
+        .iter()
+        .map(|n| get_amount(n, &steps, &mut cache))
+        .sum()
+}
+
+fn main() {
+    let input = parse(include_str!("../input.txt"));
+    println!("{}", part(&input, 25));
+    println!("{}", part(&input, 75));
+}