From 36ff2f2c3564641ee2e41fbe8a6b9cdb2d14005c Mon Sep 17 00:00:00 2001
From: Lucy <lucy@amogus.cloud>
Date: Fri, 13 Dec 2024 08:49:54 +0100
Subject: [PATCH] feat: day 11

---
 Cargo.toml               |  2 +
 inputs/day11/example.txt |  1 +
 src/day11.rs             | 79 ++++++++++++++++++++++++++++++++++++++++
 src/main.rs              |  4 ++
 4 files changed, 86 insertions(+)
 create mode 100644 inputs/day11/example.txt
 create mode 100644 src/day11.rs

diff --git a/Cargo.toml b/Cargo.toml
index 0dd9a1a..7deb2fb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ full = [
     "day8",
     "day9",
     "day10",
+    "day11",
 ]
 default = ["full"]
 day1 = []
@@ -27,6 +28,7 @@ day7 = []
 day8 = []
 day9 = []
 day10 = []
+day11 = []
 
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
diff --git a/inputs/day11/example.txt b/inputs/day11/example.txt
new file mode 100644
index 0000000..528f9d5
--- /dev/null
+++ b/inputs/day11/example.txt
@@ -0,0 +1 @@
+125 17
\ No newline at end of file
diff --git a/src/day11.rs b/src/day11.rs
new file mode 100644
index 0000000..f15e112
--- /dev/null
+++ b/src/day11.rs
@@ -0,0 +1,79 @@
+#![allow(
+    clippy::cast_sign_loss,
+    clippy::cast_possible_wrap,
+    clippy::too_many_lines
+)]
+
+use std::collections::HashMap;
+
+use tracing::debug;
+
+fn blink_v2(stones: HashMap<usize, usize>) -> HashMap<usize, usize> {
+    let mut res: HashMap<usize, usize> = HashMap::new();
+    for (stone, count) in stones {
+        match stone {
+            0 => {
+                res.insert(1, *(res.get(&1).unwrap_or(&0)) + count);
+            }
+            s if s.to_string().len() % 2 == 0 => {
+                let s_string = s.to_string();
+                let split = s_string.split_at(s_string.len() / 2);
+                let left_half = split.0.parse::<usize>().unwrap();
+                res.insert(left_half, *(res.get(&left_half).unwrap_or(&0)) + count);
+                let right_half = split.1.parse::<usize>().unwrap();
+                res.insert(right_half, *(res.get(&right_half).unwrap_or(&0)) + count);
+            }
+            v => {
+                let new_stone = v * 2024;
+                res.insert(new_stone, *(res.get(&new_stone).unwrap_or(&0)) + count);
+            }
+        }
+    }
+    res
+}
+pub fn pt1(input: &str) -> usize {
+    let mut stones: HashMap<usize, usize> = HashMap::new();
+    for stone in input
+        .split_whitespace()
+        .map(|s| s.parse::<usize>().unwrap())
+    {
+        stones.insert(stone, stones.get(&stone).unwrap_or(&0) + 1);
+    }
+    for step in 0..25 {
+        debug!("step {step}");
+        stones = blink_v2(stones);
+    }
+
+    stones.values().sum()
+}
+pub fn pt2(input: &str) -> usize {
+    let mut stones: HashMap<usize, usize> = HashMap::new();
+    for stone in input
+        .split_whitespace()
+        .map(|s| s.parse::<usize>().unwrap())
+    {
+        stones.insert(stone, stones.get(&stone).unwrap_or(&0) + 1);
+    }
+    for step in 0..75 {
+        debug!("step {step}");
+        stones = blink_v2(stones);
+    }
+
+    stones.values().sum()
+}
+
+#[cfg(test)]
+mod tests {
+    use tracing_test::traced_test;
+
+    use super::pt1;
+    use std::fs::read_to_string;
+
+    #[traced_test]
+    #[test]
+    pub fn test_pt1() {
+        let input =
+            read_to_string("./inputs/day11/example.txt").expect("Missing example.txt for day11");
+        assert_eq!(pt1(&input), 55312)
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 7311ed5..e373132 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,6 +23,8 @@ mod day08;
 mod day09;
 #[cfg(feature = "day10")]
 mod day10;
+#[cfg(feature = "day11")]
+mod day11;
 
 fn main() -> eyre::Result<()> {
     color_eyre::install()?;
@@ -49,6 +51,8 @@ fn main() -> eyre::Result<()> {
     solve_day(9, day09::pt1, day09::pt2);
     #[cfg(feature = "day10")]
     solve_day(10, day10::pt1, day10::pt2);
+    #[cfg(feature = "day11")]
+    solve_day(11, day11::pt1, day11::pt2);
     Ok(())
 }