Try gaining performance.. fail

Cargo.lock

@@ -23,6 +23,13 @@ dependencies = [
 name = "day02"
 version = "0.1.0"
 
+[[package]]
+name = "day02-gen-problem"
+version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
 [[package]]
 name = "day03"
 version = "0.1.0"

Cargo.toml

@@ -1,7 +1,8 @@
 [workspace]
-members = [ "day01", "day01-gen-problem", "day02", "day03", "day04", "day05", "day06", "day07", "day08", "day09", "day10", "day11", "day12", "day13", "day14", "day15", "day16", "day17", "day18", "day19", "day20", "day21", "day22", "day23", "day24", ]
+members = [ "day01", "day01-gen-problem", "day02", "day02-gen-problem", "day03", "day04", "day05", "day06", "day07", "day08", "day09", "day10", "day11", "day12", "day13", "day14", "day15", "day16", "day17", "day18", "day19", "day20", "day21", "day22", "day23", "day24", ]
 
 [profile.release]
+#debug = true
 panic = "abort"
 strip = "symbols"
 lto = true

day02-gen-problem/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day02-gen-problem"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rand = "0.8.5"

day02-gen-problem/src/main.rs

@@ -0,0 +1,29 @@
+use std::{fs::File, io::BufWriter, io::Write};
+
+use rand::Rng;
+
+const LINE_COUNT: usize = 20_000_000;
+
+fn main() {
+    let outfile = ::std::env::args()
+        .skip(1)
+        .next()
+        .expect("Output file as first parameter");
+    let mut outfile = BufWriter::new(File::create(outfile).expect("Can write outfile"));
+    let mut rng = rand::thread_rng();
+    (0..LINE_COUNT)
+        .map(|_| match rng.gen_range(1..=9) {
+            1 => "A X",
+            2 => "B X",
+            3 => "C X",
+            4 => "A Y",
+            5 => "B Y",
+            6 => "C Y",
+            7 => "A Z",
+            8 => "B Z",
+            9 => "C Z",
+            _ => unreachable!(),
+        })
+        .for_each(|line| writeln!(outfile, "{line}").expect("Writing works"));
+    outfile.flush().expect("Flushing works");
+}

day02/Cargo.toml

@@ -8,3 +8,6 @@ build = true
 app = true
 
 [dependencies]
+
+[features]
+first = []

day02/src/main.rs

@@ -3,37 +3,37 @@ use std::{
     io::{BufRead, BufReader},
 };
 
-// fn calculate_game_score<S: AsRef<str>>(line: S) -> usize {
-//     let line = line.as_ref();
-//     match line {
-//         "A X" => 1 + 3, // Rock    -- Rock
-//         "B X" => 1 + 0, // Paper   -> Rock
-//         "C X" => 1 + 6, // Scissor <- Rock
-//         "A Y" => 2 + 6,
-//         "B Y" => 2 + 3,
-//         "C Y" => 2 + 0,
-//         "A Z" => 3 + 0,
-//         "B Z" => 3 + 6,
-//         "C Z" => 3 + 3,
-//         _ => unreachable!(),
-//     }
-// }
-
-fn calculate_game_score<S: AsRef<str>>(line: S) -> usize {
-    let line = line.as_ref();
+fn calculate_game_score(line: String) -> usize {
+    let line = line.as_bytes();
+    let left = line[0] - b'A';
+    let right = line[2] - b'X';
+    #[cfg(feature = "first")]
     match line {
+        (0, 0) => 1 + 3,
+        (1, 0) => 1 + 0,
+        (2, 0) => 1 + 6,
+        (0, 1) => 2 + 6,
+        (1, 1) => 2 + 3,
+        (2, 1) => 2 + 0,
+        (0, 2) => 3 + 0,
+        (1, 2) => 3 + 6,
+        (2, 2) => 3 + 3,
+        _ => unreachable!(),
+    }
+    #[cfg(not(feature = "first"))]
+    match (left, right) {
         // Rock -> 1
         // Paper -> 2
         // Scissor -> 3
-        "A X" => 3 + 0,
-        "B X" => 1 + 0,
-        "C X" => 2 + 0,
-        "A Y" => 1 + 3,
-        "B Y" => 2 + 3,
-        "C Y" => 3 + 3,
-        "A Z" => 2 + 6,
-        "B Z" => 3 + 6,
-        "C Z" => 1 + 6,
+        (0, 0) => 3 + 0,
+        (1, 0) => 1 + 0,
+        (2, 0) => 2 + 0,
+        (0, 1) => 1 + 3,
+        (1, 1) => 2 + 3,
+        (2, 1) => 3 + 3,
+        (0, 2) => 2 + 6,
+        (1, 2) => 3 + 6,
+        (2, 2) => 1 + 6,
         _ => unreachable!(),
     }
 }