added some comments

src/main.rs

@@ -11,11 +11,25 @@ impl Rng {
             .duration_since(SystemTime::UNIX_EPOCH)
             .unwrap()
             .subsec_nanos() as u64;
-        Self { state: seed ^ 0x9e3779b97f4a7c15 }
+        // Allegedly
+        // It's XOR'd with the seed (`subsec_nanos()`) as a **mixing step** —
+        // the golden ratio has a property where it distributes bits very evenly across
+        // the range, so even a low-entropy seed gets spread across all 64 bits
+        // before the first LCG iteration runs
+        Self {
+            state: seed ^ 0x9e3779b97f4a7c15,
+        }
     }
 
     fn next_u64(&mut self) -> u64 {
-        self.state = self.state.wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407);
+        // Allegedly
+        // Knuth MMIX LCG constants:
+        // multiplier chosen for spectral quality (for uniform distribution)
+        // addend must be odd for full 2^64 period
+        self.state = self
+            .state
+            .wrapping_mul(6364136223846793005)
+            .wrapping_add(1442695040888963407);
         self.state
     }
 
@@ -109,7 +123,7 @@ fn main() {
     println!("Complete {ROUNDS} questions to finish a round.\n");
 
     let stdin = io::stdin();
-    let mut stdin = stdin.lock();
+    let mut stdin = stdin.lock(); // why lock?
     let mut rng = Rng::new();
     let mut stats: Vec<QuestionStats> = Vec::with_capacity(ROUNDS);
 
@@ -156,12 +170,16 @@ fn main() {
 }
 
 fn print_summary(stats: &[QuestionStats]) {
+    // voodoo
     let total_time: Duration = stats.iter().map(|s| s.time_taken).sum();
     let total_mistakes: u32 = stats.iter().map(|s| s.mistakes).sum();
     let perfect = stats.iter().filter(|s| s.mistakes == 0).count();
 
     println!("=== Round Complete ===\n");
-    println!("{:<5} {:<12} {:<8} {:>10}  {:>8}", "#", "Question", "Answer", "Time (s)", "Mistakes");
+    println!(
+        "{:<5} {:<12} {:<8} {:>10}  {:>8}",
+        "#", "Question", "Answer", "Time (s)", "Mistakes"
+    );
     println!("{}", "-".repeat(50));
 
     for (i, s) in stats.iter().enumerate() {
@@ -179,7 +197,11 @@ fn print_summary(stats: &[QuestionStats]) {
     println!("{}", "-".repeat(50));
     println!(
         "{:<5} {:<12} {:<8} {:>10.2}  {:>8}",
-        "Tot", "", "", total_time.as_secs_f64(), total_mistakes
+        "Tot",
+        "",
+        "",
+        total_time.as_secs_f64(),
+        total_mistakes
     );
-    println!("\nPerfect (no mistakes): {}/{}", perfect, stats.len());
+    println!("\nScore: {}/{}", perfect, stats.len());
 }