Dual move optimization (WIP, useless?)

Cargo.lock

@@ -28,6 +28,12 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "either"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
+
 [[package]]
 name = "encode_unicode"
 version = "0.3.6"
@@ -57,6 +63,15 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37d572918e350e82412fe766d24b15e6682fb2ed2bbe018280caa810397cb319"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -87,6 +102,7 @@ version = "0.1.0"
 dependencies = [
  "byteorder",
  "indicatif",
+ "itertools",
  "rand",
 ]
 

Cargo.toml

@@ -10,6 +10,7 @@ edition = "2018"
 byteorder = "1.3.4"
 rand = "0.8.0"
 indicatif = "0.15.0"
+itertools = "0.10.0"
 
 [[bin]]
 name = "prague"

src/city.rs

@@ -34,7 +34,7 @@ impl City {
         City { prices, buyable_house_count }
     }
 
-    pub fn get_price(&self, house: &House) -> u16 {
+    pub fn get_price(&self, house: House) -> u16 {
         self.prices[house.y * SIZE + house.x]
     }
 
@@ -42,8 +42,8 @@ impl City {
         self.prices[y * SIZE + x]
     }
 
-    pub fn is_house(&self, house: &House) -> bool {
-        self.get_price(&house) > 0
+    pub fn is_house(&self, house: House) -> bool {
+        self.get_price(house) > 0
     }
 
     pub fn is_house_xy(&self, x: usize, y: usize) -> bool {
@@ -76,6 +76,7 @@ impl House {
 }
 
 /// Rectangle - a 2D range with inclusive bounds
+#[derive(Clone, Copy)]
 pub struct Rectangle {
     /// The smaller x coordinate.
     pub left: usize,
@@ -166,7 +167,7 @@ impl<'a> HouseLayout<'a> {
     }
 
     pub fn is_valid(&self) -> bool {
-        self.reachable_houses == self.city.buyable_house_count
+        self.reachable_houses == self.city.get_house_count()
     }
 
     pub fn price(&self) -> u32 {
@@ -180,8 +181,8 @@ impl<'a> HouseLayout<'a> {
 
 fn get_price(city: &City, houses: &Vec<House>) -> u32 {
     let mut price = 0u32;
-    for house in houses {
-        price += city.get_price(&house) as u32;
+    for &house in houses {
+        price += city.get_price(house) as u32;
     }
 
     price
@@ -200,7 +201,7 @@ fn is_valid(city: &City, houses: &Vec<House>) -> Option<u32> {
                 reachable[y as usize * SIZE + x as usize] = true;
             }
         }
-        price += city.get_price(&house) as u32;
+        price += city.get_price(*house) as u32;
     }
 
     for y in 0..SIZE {

src/main.rs

@@ -35,6 +35,12 @@ fn main() {
                 improved = true;
             }
             eprintln!("Finished pairwise house merge");
+            //eprintln!("Starting pairwise house move...");
+            //if optimization::improve_move_houses_pairwise(&mut layout) {
+            //    dump_layout(&layout, &mut best_price, seed);
+            //    improved = true;
+            //}
+            //eprintln!("Finished pairwise house move");
             if !improved {
                 break;
             }

src/optimization.rs

@@ -1,13 +1,14 @@
 use std::collections::HashSet;
 use rand::prelude::{SliceRandom, StdRng};
 use crate::city::{Rectangle, HOUSE_RANGE, SIZE, House, HouseLayout};
+use itertools::iproduct;
 
 pub enum RectangleSearchError {
     Useless,
     Unsatisfiable
 }
 
-pub fn get_valid_move_rectangle_multiple(layout: &HouseLayout, houses: &Vec<House>) -> Result<Rectangle, RectangleSearchError> {
+fn get_valid_move_rectangle_multiple(layout: &HouseLayout, houses: &Vec<House>) -> Result<Rectangle, RectangleSearchError> {
     // This is a generalization of get_valid_move_rectangle, it's basically the same thing,
     // just with a dynamic rectangles_containing_count
 
@@ -67,7 +68,7 @@ pub fn get_valid_move_rectangle_multiple(layout: &HouseLayout, houses: &Vec<Hous
     Ok(Rectangle { left, right, top, bottom })
 }
 
-pub fn get_valid_move_rectangle(layout: &HouseLayout, house: House) -> Result<Rectangle, RectangleSearchError> {
+fn get_valid_move_rectangle(layout: &HouseLayout, house: House) -> Result<Rectangle, RectangleSearchError> {
     // We first establish a bounding box for an that has to be covered if the house is removed.
     let mut covered_rect: Option<Rectangle> = None;
 
@@ -143,13 +144,13 @@ pub fn improve_move_individual_houses(layout: &mut HouseLayout, mut rng: &mut St
         let mut new_candidates = Vec::new();
         for new_y in move_rectangle.top..=move_rectangle.bottom {
             for new_x in move_rectangle.left..=move_rectangle.right {
-                if layout.city.is_house_xy(new_x, new_y) && layout.city.get_price_xy(new_x, new_y) < layout.city.get_price(&house) {
+                if layout.city.is_house_xy(new_x, new_y) && layout.city.get_price_xy(new_x, new_y) < layout.city.get_price(house) {
                     new_candidates.push(House::new(new_x, new_y));
                 }
             }
         }
 
-        new_candidates.sort_by(|a, b| layout.city.get_price(&a).cmp(&layout.city.get_price(&b)));
+        new_candidates.sort_by(|a, b| layout.city.get_price(*a).cmp(&layout.city.get_price(*b)));
         if new_candidates.len() == 0 {
             //eprintln!("Did not find candidate");
         } else {
@@ -222,7 +223,7 @@ pub fn improve_merge_pairwise(layout: &mut HouseLayout) -> bool {
                                 }
                             }
                             if let Some((x, y, price)) = cheapest {
-                                if price >= layout.city.get_price(&house1) + layout.city.get_price(&house2) {
+                                if price >= layout.city.get_price(house1) + layout.city.get_price(house2) {
                                     // Merging not worth
                                     //eprintln!("Merging not worth!");
                                 } else {
@@ -262,3 +263,158 @@ pub fn improve_merge_pairwise(layout: &mut HouseLayout) -> bool {
 
     improved
 }
+
+pub fn improve_move_houses_pairwise(layout: &mut HouseLayout) -> bool {
+    // TODO: Implement layout move house to avoid changing indices
+    for i in 0..layout.houses().len() {
+        for j in i + 1..layout.houses().len() {
+            let house1 = layout.houses()[i];
+            let house2 = layout.houses()[j];
+            let x_dist = (house1.x as i32 - house2.x as i32).abs() as usize;
+            let y_dist = (house1.y as i32 - house2.y as i32).abs() as usize;
+            if x_dist > 2 * HOUSE_RANGE + 1 || y_dist > 2 * HOUSE_RANGE + 1 {
+                // Not close enough to overlap or touch areas (can move on its own)
+                continue;
+            }
+
+            if let Some(distances) = get_dual_move_distances(&layout, i, j) {
+                eprintln!("Houses {} {} move distances: L{} R{} T{} B{}", i, j, distances.left, distances.right, distances.up, distances.down);
+                let mut best_move = None;
+
+                let old_price = layout.city.get_price(house1) + layout.city.get_price(house2);
+
+                let left_deltas = (1..distances.left).map(|x| (-(x as i32), 0));
+                let right_deltas = (1..distances.right).map(|x| (x as i32, 0));
+                let up_deltas = (1..distances.up).map(|x| (0, -(x as i32)));
+                let down_deltas = (1..distances.down).map(|x| (0, x as i32));
+                let move_deltas = left_deltas.chain(right_deltas).chain(up_deltas).chain(down_deltas);
+
+                for (x_delta, y_delta) in move_deltas {
+                    let new_house1 = House::new(
+                        (house1.x as i32 + x_delta) as usize,
+                        (house1.y as i32 + y_delta) as usize,
+                    );
+                    let new_house2 = House::new(
+                        (house2.x as i32 + x_delta) as usize,
+                        (house2.y as i32 + y_delta) as usize,
+                    );
+
+                    if !layout.city.is_house(new_house1) || !layout.city.is_house(new_house2) {
+                        continue;
+                    }
+
+                    let new_price = layout.city.get_price(new_house1) + layout.city.get_price(new_house2);
+                    eprintln!("Move x{} y{}, diff {} (price {}->{})", x_delta, y_delta, new_price as i32 - old_price as i32, old_price, new_price);
+
+                    if new_price < old_price {
+                        match best_move {
+                            None => best_move = Some((x_delta, y_delta, new_price)),
+                            Some((_, _, best_price)) if new_price < best_price => {
+                                best_move = Some((x_delta, y_delta, new_price));
+                            }
+                            _ => {}
+                        }
+                    }
+                }
+
+                if let Some((x_delta, y_delta, best_price)) = best_move {
+                    eprintln!("Best move x{} y{}, diff {} (price {}->{})", x_delta, y_delta, best_price as i32 - old_price as i32, old_price, best_price);
+                    // TODO: IMPLEMENT MOVE
+                } else {
+                    eprintln!("No move worth it.");
+                }
+            }
+        }
+    }
+
+    unimplemented!()
+}
+
+struct MoveDistances {
+    left: usize,
+    right: usize,
+    up: usize,
+    down: usize,
+}
+
+fn get_dual_move_distances(layout: &HouseLayout, house1_index: usize, house2_index: usize) -> Option<MoveDistances> {
+    let house1 = layout.houses()[house1_index];
+    let house2 = layout.houses()[house2_index];
+
+    let rect1 = house1.range_rectangle();
+    let rect2 = house2.range_rectangle();
+
+    let top1 = rect1.top.min(rect2.top);
+    let top2 = rect1.top.max(rect2.top);
+    let bottom1 = rect1.bottom.min(rect2.bottom);
+    let bottom2 = rect1.bottom.max(rect2.bottom);
+    let left1 = rect1.left.min(rect2.left);
+    let left2 = rect1.left.max(rect2.left);
+    let right1 = rect1.right.min(rect2.right);
+    let right2 = rect1.right.max(rect2.right);
+
+    let left_rect = if house1.x <= house2.x { rect1 } else { rect2 };
+    let right_rect = if house1.x <= house2.x { rect2 } else { rect1 };
+    let top_rect = if house1.y <= house2.y { rect1 } else { rect2 };
+    let bottom_rect = if house1.y <= house2.y { rect2 } else { rect1 };
+
+    let margin_left = left1..left2;
+    let shared_x = left2..=right1;
+    let margin_right = right1 + 1..=right2;
+    let margin_top = top1..top2;
+    let shared_y = top2..=bottom1;
+    let margin_bottom = bottom1 + 1..=bottom2;
+
+    let mut top_distance = SIZE;
+    let mut bottom_distance = SIZE;
+    let mut right_distance = SIZE;
+    let mut left_distance = SIZE;
+
+    // We check the same tile twice if it's in both rectangles (and both shared_x and shared_y),
+    // this could be made more efficient by dividing the rectangles into 5 zones.
+    let rect1 = iproduct!(rect1.top..=rect1.bottom, rect1.left..=rect1.right);
+    let rect2 = iproduct!(rect2.top..=rect2.bottom, rect2.left..=rect2.right);
+    for (y, x) in rect1.chain(rect2) {
+        let shared_both = shared_x.contains(&x) && shared_y.contains(&y);
+        let min_cover_count = if shared_both { 2 } else { 1 };
+        if !layout.city.is_house_xy(x, y) && layout.cover_count_xy(x, y) != min_cover_count {
+            continue;
+        }
+
+        if margin_left.contains(&x) {
+            top_distance = top_distance.min(y - left_rect.top);
+            bottom_distance = bottom_distance.min(left_rect.bottom - y);
+        } else if shared_x.contains(&x) {
+            top_distance = top_distance.min(y - left_rect.top.min(right_rect.top));
+            bottom_distance = bottom_distance.min(left_rect.bottom.max(right_rect.bottom) - y);
+        } else if margin_right.contains(&x) {
+            top_distance = top_distance.min(y - right_rect.top);
+            bottom_distance = bottom_distance.min(right_rect.bottom - y);
+        } else {
+            unreachable!();
+        }
+
+        if margin_top.contains(&y) {
+            left_distance = left_distance.min(x - top_rect.left);
+            right_distance = right_distance.min(top_rect.right - x);
+        } else if shared_y.contains(&y) {
+            left_distance = left_distance.min(x - bottom_rect.left.min(top_rect.left));
+            right_distance = right_distance.min(bottom_rect.right.max(top_rect.right) - x);
+        } else if margin_bottom.contains(&y) {
+            left_distance = left_distance.min(x - bottom_rect.left);
+            right_distance = right_distance.min(bottom_rect.right - x);
+        } else {
+            unreachable!()
+        }
+    }
+
+    // TODO: Handle properly
+    assert_ne!(top_distance, SIZE);
+
+    Some(MoveDistances {
+        left: left_distance,
+        right: right_distance,
+        up: top_distance,
+        down: bottom_distance
+    })
+}