Add second genetic algorithm.

src/layout/mod.rs

@@ -105,6 +105,48 @@ impl<'a> GeneticAlgorithm<'a> {
     }
 }
 
+pub fn genetic_algorithm2<'a, R: Rng + ?Sized>(
+    problem: &'a Problem,
+    new_layouts: usize,
+    mutation_timeout: usize,
+    rng: &'_ mut R,
+) -> PathLayout<'a> {
+    let mut m = (0..new_layouts)
+        .map(|_| valid_path_layout(problem, rng))
+        .min_by_key(|p| p.score())
+        .unwrap();
+
+    m.print_visualization();
+
+    let mut last_improvement = 0;
+    let mut count = 0;
+
+    while last_improvement < mutation_timeout {
+        last_improvement += 1;
+        count += 1;
+        if let Some(p) = PathLayout::new(m.layout.mutate(rng)) {
+            if p.score() < m.score() {
+                m = p;
+                println!("Step: {count}");
+                m.print_visualization();
+                last_improvement = 0;
+            }
+        }
+    }
+    m
+}
+
+pub fn valid_path_layout<'a, R: Rng + ?Sized>(
+    problem: &'a Problem,
+    rng: &'_ mut R,
+) -> PathLayout<'a> {
+    loop {
+        if let Some(p) = PathLayout::new(Layout::new(problem, rng)) {
+            return p;
+        }
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub(crate) struct Block {
     pub(crate) size: Position,
@@ -189,7 +231,7 @@ impl<'a> PathLayout<'a> {
         })
     }
 
-    fn score(&self) -> usize {
+    pub fn score(&self) -> usize {
         self.score
     }
 }
@@ -347,7 +389,7 @@ impl Layout<'_> {
         loop {
             let p = r.choose_weighted(rng, |i| i.1).unwrap();
 
-            if p.0(&mut s, rng) && rng.gen_bool(0.2) {
+            if p.0(&mut s, rng) && rng.gen_bool(0.05) {
                 break;
             }
         }