Combining forever; adding to DB

src/combine-layouts.rs

@@ -1,6 +1,7 @@
 use db::LayoutDB;
-use city::{City, House, SIZE};
+use city::{City, SIZE};
 use itertools::Itertools;
+use crate::combine::transpose_layout;
 
 mod city;
 mod db;
@@ -13,21 +14,27 @@ fn main() {
     let city = City::read_from_file("01.in");
     eprintln!("Loaded the city file, {} houses", city.get_house_count());
 
-    let layouts = db.layouts();
+    eprintln!("Building a transposed city...");
-    let sorted: Vec<_> = layouts.iter().sorted_by(|x, y| city::get_price(&city, x.houses()).cmp(&city::get_price(&city, y.houses()))).collect();
-
-    const TOP_LAYOUT_COUNT: usize = 100;
-
-    let chosen_layouts: Vec<_> = sorted.iter().take(TOP_LAYOUT_COUNT).map(|l| l.houses().clone()).collect();
-
-    //eprintln!("Starting to combine {} top houses DB; vertical cuts", TOP_LAYOUT_COUNT);
-    //combine::try_combine(&city, &chosen_layouts, &chosen_layouts, false);
-
-    eprintln!("Transposing...");
     let transposed_city = transpose_city(&city);
-    let transposed_chosen_layouts: Vec<_> = chosen_layouts.iter().map(|x| transpose_layout(x)).collect();
+    eprintln!("Finished building a transposed city");
-    eprintln!("Starting to combine {} top houses DB; horizontal cuts", TOP_LAYOUT_COUNT);
+
-    combine::try_combine(&transposed_city, &transposed_chosen_layouts, &transposed_chosen_layouts, true);
+    loop {
+        let sorted: Vec<_> = db.layouts().iter()
+            .sorted_by(|x, y| city::get_price(&city, x.houses()).cmp(&city::get_price(&city, y.houses())))
+            .map(|layout| layout.clone())
+            .collect();
+
+        const TOP_LAYOUT_COUNT: usize = 1000;
+
+        let chosen_layouts: Vec<_> = sorted.iter().take(TOP_LAYOUT_COUNT).map(|l| l.houses().clone()).collect();
+
+        eprintln!("Starting to combine {} top houses DB; vertical cuts", TOP_LAYOUT_COUNT);
+        combine::try_combine(&city, &chosen_layouts, &chosen_layouts, &mut db, false);
+
+        let transposed_chosen_layouts: Vec<_> = chosen_layouts.iter().map(|x| transpose_layout(x)).collect();
+        eprintln!("Starting to combine {} top houses DB; horizontal cuts", TOP_LAYOUT_COUNT);
+        combine::try_combine(&transposed_city, &transposed_chosen_layouts, &transposed_chosen_layouts, &mut db, true);
+    }
 }
 
 fn transpose_city(city: &City) -> City {
@@ -42,12 +49,3 @@ fn transpose_city(city: &City) -> City {
 
     City::new(transposed_prices)
 }
-
-fn transpose_layout(houses: &Vec<House>) -> Vec<House> {
-    let mut transposed = Vec::new();
-    for house in houses {
-        transposed.push(House::new(house.y, house.x));
-    }
-
-    transposed
-}

src/combine.rs

@@ -1,11 +1,12 @@
 use crate::city;
-use crate::city::{City, House, SIZE, HOUSE_RANGE};
+use crate::db::LayoutDB;
+use crate::city::{City, House, SIZE};
 use itertools::Itertools;
 use itertools::iproduct;
 use std::collections::VecDeque;
 use std::collections::vec_deque::Iter;
 
-pub fn try_combine(city: &City, left_layouts: &Vec<Vec<House>>, right_layouts: &Vec<Vec<House>>, print_transposed: bool) {
+pub fn try_combine(city: &City, left_layouts: &Vec<Vec<House>>, right_layouts: &Vec<Vec<House>>, db: &mut LayoutDB, transposed: bool) {
     // Sorted in reverse so we can remove from the end
     let mut left_houses_sorted: Vec<Vec<House>> = left_layouts.iter()
         .map(|l| l.iter().sorted_by(|h1, h2| h2.x.cmp(&h1.x)).map(|x| *x).collect())
@@ -30,10 +31,13 @@ pub fn try_combine(city: &City, left_layouts: &Vec<Vec<House>>, right_layouts: &
         rights.push(right);
     }
 
-    let mut best_price = None;
+    let mut best_price = left_layouts.iter().chain(right_layouts.iter())
+        .map(|layout| city::get_price(&city, layout))
+        .min();
+
     // x is the last left coordinate, x+1 is right
     for x in 0..SIZE {
-        if print_transposed {
+        if transposed {
             eprintln!("Starting y {}", x);
         } else {
             eprintln!("Starting x {}", x);
@@ -63,7 +67,7 @@ pub fn try_combine(city: &City, left_layouts: &Vec<Vec<House>>, right_layouts: &
         }
 
         let pairs: Vec<_> = iproduct!(lefts.iter().enumerate(), rights.iter().enumerate())
-            .filter(|((left_i, left), (right_i, right))| left_i != right_i)
+            .filter(|((left_i, _), (right_i, _))| left_i != right_i)
             .map(|((left_i, left), (right_i, right))| (left, right, left.price + right.price, left_i, right_i))
             .sorted_by(|(_, _, price1, _, _), (_, _, price2, _, _)| price1.cmp(&price2))
             .collect();
@@ -74,23 +78,20 @@ pub fn try_combine(city: &City, left_layouts: &Vec<Vec<House>>, right_layouts: &
             if is_compatible(city, &left, &right) {
                 if best_price.is_none() || price < best_price.unwrap() {
                     best_price = Some(price);
-                    if print_transposed {
+                    let axis = if transposed { "y" } else { "x" };
-                        eprintln!("{} - new best score, cut on y {}, left {} - right {}, printing", price, x, left_i, right_i);
+                    eprintln!("{} - new best score, cut on {} {}, left {} - right {}, printing", axis, price, x, left_i, right_i);
-                        println!("{} - new best score, cut on y {}, left {} - right {}", price, x, left_i, right_i);
+                    println!("{} - new best score, cut on {} {}, left {} - right {}", axis, price, x, left_i, right_i);
-                        let new_houses: Vec<_> = left.houses().chain(right.houses()).collect();
+                    let mut new_houses: Vec<_> = left.houses().copied().chain(right.houses().copied()).collect();
-                        println!("{}", new_houses.len());
+                    if transposed {
-                        for house in new_houses {
+                        new_houses = transpose_layout(&new_houses);
-                            println!("{} {}", house.x, house.y);
-                        }
-                    } else {
-                        eprintln!("{} - new best score, cut on x {}, left {} - right {}, printing", price, x, left_i, right_i);
-                        println!("{} - new best score, cut on x {}, left {} - right {}", price, x, left_i, right_i);
-                        let new_houses: Vec<_> = left.houses().chain(right.houses()).collect();
-                        println!("{}", new_houses.len());
-                        for house in new_houses {
-                            println!("{} {}", house.y, house.x);
-                        }
                     }
+                    println!("{}", new_houses.len());
+                    for house in &new_houses {
+                        println!("{} {}", house.y, house.x);
+                    }
+
+                    // We only add best results to avoid overfilling the database with similar layouts
+                    db.add_layout(&new_houses, true);
                 }
                 compatibles += 1;
 
@@ -111,7 +112,7 @@ fn is_compatible(city: &City, left: &LeftLine, right: &RightLine) -> bool {
         let min_right_covered_x = right.get_min_covered_x(y);
 
         // This range will often be empty
-        for x in (max_left_covered_x+1)..min_right_covered_x {
+        for x in (max_left_covered_x + 1)..min_right_covered_x {
             if city.is_house_xy(x, y) {
                 return false;
             }
@@ -124,13 +125,13 @@ fn is_compatible(city: &City, left: &LeftLine, right: &RightLine) -> bool {
 struct LeftLine {
     covers: Vec<usize>,
     houses: Vec<House>,
-    price: u32
+    price: u32,
 }
 
 struct RightLine {
     covers: Vec<usize>,
     houses: VecDeque<House>,
-    price: u32
+    price: u32,
 }
 
 impl LeftLine {
@@ -138,7 +139,7 @@ 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 }
     }
 
     pub fn add_house(&mut self, house: House, city: &City) {
@@ -168,7 +169,7 @@ 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 }
     }
 
     pub fn add_house(&mut self, house: House, city: &City) {
@@ -228,3 +229,12 @@ impl RightLine {
         self.houses.iter()
     }
 }
+
+pub fn transpose_layout(houses: &Vec<House>) -> Vec<House> {
+    let mut transposed = Vec::new();
+    for house in houses {
+        transposed.push(House::new(house.y, house.x));
+    }
+
+    transposed
+}

src/db.rs

@@ -1,5 +1,5 @@
 use crate::city::House;
-use rusqlite::{Connection, NO_PARAMS, params, Result, Transaction};
+use rusqlite::{Connection, NO_PARAMS, params, Result};
 use std::collections::HashMap;
 
 pub struct LayoutDB {