Cache by last updates of left and right side instead of just coord

src/combine.rs

@@ -18,7 +18,7 @@ struct RightState<'a> {
 }
 
 pub struct CompatibilityCache {
-    map: HashMap<(usize, usize, usize, bool), bool>
+    map: HashMap<(usize, usize, usize, usize, bool), bool>
 }
 
 impl CompatibilityCache {
@@ -28,12 +28,12 @@ impl CompatibilityCache {
         }
     }
 
-    pub fn is_compatible(&self, left_layout: &SavedLayout, right_layout: &SavedLayout, index: usize, y_axis: bool) -> Option<&bool> {
+    pub fn is_compatible(&self, left_layout: &SavedLayout, right_layout: &SavedLayout, left_update_index: usize, right_update_index: usize, y_axis: bool) -> Option<&bool> {
-        self.map.get(&(left_layout.id(), right_layout.id(), index, y_axis))
+        self.map.get(&(left_layout.id(), right_layout.id(), left_update_index, right_update_index, y_axis))
     }
 
-    pub fn set_compatible(&mut self, left_layout: &SavedLayout, right_layout: &SavedLayout, index: usize, y_axis: bool, compatible: bool) {
+    pub fn set_compatible(&mut self, left_layout: &SavedLayout, right_layout: &SavedLayout, left_update_index: usize, right_update_index: usize, y_axis: bool, compatible: bool) {
-        self.map.insert((left_layout.id(), right_layout.id(), index, y_axis), compatible);
+        self.map.insert((left_layout.id(), right_layout.id(), left_update_index, right_update_index, y_axis), compatible);
     }
 }
 
@@ -115,10 +115,10 @@ pub fn try_combine(city: &City, left_layouts: &Vec<SavedLayout>, right_layouts:
                     break;
                 }
             }
-            let compatible = match cache.is_compatible(left.layout, right.layout, x, transposed) {
+            let compatible = match cache.is_compatible(left.layout, right.layout, left.line.last_update_x, right.line.last_update_x, transposed) {
                 None => {
                     let compatible = is_compatible(city, &left.line, &right.line);
-                    cache.set_compatible(left.layout, right.layout, x, transposed, compatible);
+                    cache.set_compatible(left.layout, right.layout, left.line.last_update_x, right.line.last_update_x, transposed, compatible);
                     compatible
                 }
                 Some(compatible) => {
@@ -179,12 +179,14 @@ struct LeftLine {
     covers: Vec<usize>,
     houses: Vec<House>,
     price: u32,
+    last_update_x: usize
 }
 
 struct RightLine {
     covers: Vec<usize>,
     houses: VecDeque<House>,
     price: u32,
+    last_update_x: usize
 }
 
 impl LeftLine {
@@ -192,7 +194,7 @@ impl LeftLine {
         // XXX: Careful, default of 0 includes covering first vertical line
         let covers = vec![0; SIZE];
         let houses = Vec::new();
-        LeftLine { covers, houses, price: 0 }
+        LeftLine { covers, houses, price: 0, last_update_x: 0 }
     }
 
     pub fn add_house(&mut self, house: House, city: &City) {
@@ -203,6 +205,7 @@ impl LeftLine {
         }
         self.price += city.get_price(house) as u32;
         self.houses.push(house);
+        self.last_update_x = house.x;
     }
 
     pub fn get_max_covered_x(&self, y: usize) -> usize {
@@ -222,7 +225,7 @@ impl RightLine {
     pub fn new() -> Self {
         let covers = vec![usize::MAX; SIZE];
         let houses = VecDeque::new();
-        RightLine { covers, houses, price: 0 }
+        RightLine { covers, houses, price: 0, last_update_x: 0 }
     }
 
     pub fn add_house(&mut self, house: House, city: &City) {
@@ -233,7 +236,8 @@ impl RightLine {
         }
 
         self.houses.push_back(house);
-        self.price += city.get_price(house) as u32
+        self.price += city.get_price(house) as u32;
+        self.last_update_x = house.x;
     }
 
     pub fn remove_houses(&mut self, x: usize, city: &City) {
@@ -264,6 +268,7 @@ impl RightLine {
                 }
 
                 self.price -= city.get_price(removed_house) as u32;
+                self.last_update_x = removed_house.x;
             } else {
                 break;
             }