solver

src/main.rs

@@ -1,9 +1,10 @@
 use palette::{IntoColor, OklabHue, Oklch, Srgb};
 use std::{
-    collections::{HashMap, HashSet},
+    collections::{BinaryHeap, HashMap, HashSet, VecDeque},
     fmt::Display,
-    io::{self, Read, Write, stdin, stdout},
-    num::NonZero,
+    hash::{DefaultHasher, Hash, Hasher},
+    io::{self, Write, stdin, stdout},
+    num::{self, NonZero},
     ops::ControlFlow,
 };
 
@@ -36,6 +37,14 @@ impl Display for Ring {
         let color: Srgb = color.into_color();
         let color: Srgb<u8> = color.into_format();
 
+        if f.alternate() {
+            write!(
+                f,
+                "{}{BLOCK}{:^5}{BLOCK}{RESET}",
+                crate_cli_color((color.red, color.green, color.blue)),
+                self.0
+            )
+        } else {
             write!(
                 f,
                 "{}{BLOCK}{BLOCK}{BLOCK}{BLOCK}{BLOCK}{BLOCK}{BLOCK}{RESET}",
@@ -43,8 +52,9 @@ impl Display for Ring {
             )
         }
     }
+}
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Tower<const TOWER_HEIGHT: usize = 4> {
     pub rings: [Option<Ring>; TOWER_HEIGHT],
 }
@@ -70,6 +80,34 @@ impl<const TOWER_HEIGHT: usize> Tower<TOWER_HEIGHT> {
         tower
     }
 
+    fn burried_score(&self) -> usize {
+        let mut ring_type = None;
+        let mut same_ring_type_score = 0;
+        let mut max_same_ring_type_score = 0;
+        let mut burried_score = 0;
+
+        for i in self.rings.iter().rev() {
+            if let Some(ring) = i {
+                if let Some(existing_ring_type) = ring_type {
+                    if existing_ring_type == *ring {
+                        same_ring_type_score += 2;
+                    } else {
+                        max_same_ring_type_score =
+                            max_same_ring_type_score.max(same_ring_type_score);
+                        burried_score += 2usize.pow(max_same_ring_type_score);
+                        same_ring_type_score = 0;
+                        ring_type = Some(*ring);
+                    }
+                } else {
+                    same_ring_type_score = 0;
+                    ring_type = Some(*ring);
+                }
+            }
+        }
+
+        burried_score
+    }
+
     fn get_movable_top(&self) -> Result<(Ring, usize), MoveError> {
         let mut topmost_ring = None;
         let mut count = 0;
@@ -112,7 +150,11 @@ impl<const TOWER_HEIGHT: usize> Tower<TOWER_HEIGHT> {
         assert_eq!(num, 0);
     }
 
-    fn add_movable_top(&mut self, (ring, num): (Ring, usize)) -> Result<usize, MoveError> {
+    fn add_movable_top(
+        &mut self,
+        (ring, num): (Ring, usize),
+        dummy: bool,
+    ) -> Result<usize, MoveError> {
         if self.top_ring().is_some_and(|top| top != ring) {
             return Err(MoveError::DestinationWrongTop);
         }
@@ -120,6 +162,10 @@ impl<const TOWER_HEIGHT: usize> Tower<TOWER_HEIGHT> {
         let height_left = TOWER_HEIGHT - self.height();
         let num_rings_moved = num.min(height_left);
 
+        if dummy {
+            return Ok(num_rings_moved);
+        }
+
         self.rings
             .iter_mut()
             .filter(|i| i.is_none())
@@ -189,6 +235,7 @@ pub enum MoveError {
     SourceEmpty,
 }
 
+#[derive(Debug, Clone, Copy)]
 pub struct Move {
     pub from_tower: usize,
     pub to_tower: usize,
@@ -233,30 +280,180 @@ impl<const TOWER_HEIGHT: usize> Game<TOWER_HEIGHT> {
         Self { ring_sets, towers }
     }
 
-    pub fn make_move(&mut self, m: Move) -> Result<usize, MoveError> {
+    pub fn possible_moves(&mut self) -> Vec<Move> {
+        let mut res = Vec::new();
+
+        for from_tower in 0..self.towers.len() {
+            for to_tower in 0..self.towers.len() {
+                if from_tower == to_tower {
+                    continue;
+                }
+
+                let m = Move::new(from_tower, to_tower);
+                if self.try_make_move(m, true).is_ok() {
+                    res.push(m);
+                }
+            }
+        }
+
+        res
+    }
+
+    fn burried_ring_score(&self) -> usize {
+        self.towers.iter().map(|i| i.burried_score()).sum()
+    }
+
+    pub fn solve(&self) -> Option<Vec<Move>> {
+        let mut working_instance = Self {
+            towers: Vec::new(),
+            ring_sets: self.ring_sets.clone(),
+        };
+
+        #[derive(Clone)]
+        struct State<const TOWER_HEIGHT: usize> {
+            towers: Vec<Tower<TOWER_HEIGHT>>,
+            m: Move,
+            parent_index: usize,
+        }
+        impl<const TOWER_HEIGHT: usize> Hash for State<TOWER_HEIGHT> {
+            fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+                self.towers.hash(state);
+            }
+        }
+
+        let hash_state = |s: &[Tower<TOWER_HEIGHT>]| {
+            let mut hasher = DefaultHasher::default();
+
+            for x in s.iter().filter(|i| i.height() != 0).enumerate() {
+                x.hash(&mut hasher);
+            }
+
+            hasher.finish()
+        };
+
+        #[derive(PartialEq, PartialOrd)]
+        struct Ordf32(f32);
+        impl Eq for Ordf32 {}
+        impl Ord for Ordf32 {
+            fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+                self.0.total_cmp(&other.0)
+            }
+        }
+
+        let mut states = Vec::new();
+        let mut todo = BinaryHeap::<(Ordf32, usize, usize)>::new();
+        let mut had = HashSet::new();
+        let mut ctr = 0;
+
+        states.push(State {
+            towers: self.towers.clone(),
+            parent_index: 0,
+            m: Move::new(0, 0),
+        });
+        todo.push((Ordf32(0.0), 1000000000, 0));
+
+        while let Some((score, depth, state_index)) = todo.pop() {
+            ctr += 1;
+            let state = states[state_index].clone();
+
+            let hash = hash_state(&state.towers);
+
+            // already had
+            if had.contains(&hash) {
+                continue;
+            }
+            had.insert(hash);
+
+            working_instance.towers = state.towers.clone();
+
+            if ctr % 100000 == 0 {
+                println!("{working_instance}");
+                println!("{} {depth}", score.0);
+                stdout().flush().unwrap();
+                stdin().read_line(&mut String::new()).unwrap();
+            }
+            if working_instance.check_done() {
+                println!("done!");
+                let mut res = Vec::new();
+
+                let mut curr = state_index;
+                while curr != 0 {
+                    res.push(states[curr].m);
+                    curr = states[curr].parent_index;
+                }
+
+                res.reverse();
+
+                return Some(res);
+            }
+
+            for m in working_instance.possible_moves() {
+                working_instance.towers = state.towers.clone();
+                working_instance.make_move(m).unwrap();
+
+                let num_solved = working_instance.num_solved();
+                let brs = working_instance.burried_ring_score();
+
+                let new_state_hash = hash_state(&working_instance.towers);
+                if had.contains(&new_state_hash) {
+                    continue;
+                }
+
+                let new_state_index = states.len();
+                states.push(State {
+                    towers: working_instance.towers.clone(),
+                    parent_index: state_index,
+                    m,
+                });
+
+                let score = (num_solved as f32 * 10.0) + (-(brs as f32) * 100.0);
+
+                todo.push((Ordf32(score), depth - 1, new_state_index));
+            }
+        }
+
+        None
+    }
+
+    pub fn try_make_move(&mut self, m: Move, dummy: bool) -> Result<usize, MoveError> {
         let Move {
             from_tower,
             to_tower,
         } = m;
 
         let (ring, mut num) = self.towers[from_tower].get_movable_top()?;
-        num = self.towers[to_tower].add_movable_top((ring, num))?;
+        num = self.towers[to_tower].add_movable_top((ring, num), dummy)?;
+
+        if dummy {
+            return Ok(num);
+        }
+
         self.towers[from_tower].remove_movable_top((ring, num));
 
         Ok(num)
     }
 
+    pub fn make_move(&mut self, m: Move) -> Result<usize, MoveError> {
+        self.try_make_move(m, false)
+    }
+
     pub fn check_done(&self) -> bool {
+        self.num_solved() == self.towers.len()
+    }
+
+    pub fn num_solved(&self) -> usize {
+        let mut num_solved = 0;
         for t in &self.towers {
             t.check();
 
             // If the tower itself didn't have matching rings, return false
             let Some((ring_type, c)) = t.count_if_single_ring_type() else {
-                return false;
+                continue;
             };
 
-            // If the tower had no rings, continue
+            // If the tower had no rings, trivially solved
             if c == 0 {
+                num_solved += 1;
                 continue;
             }
 
@@ -265,11 +462,13 @@ impl<const TOWER_HEIGHT: usize> Game<TOWER_HEIGHT> {
             // if this tower has only a subset of the total, we're not done.
             let ring_type = ring_type.unwrap();
             if *self.ring_sets.get(&ring_type).unwrap() != c {
-                return false;
-            }
+                continue;
             }
 
-        true
+            num_solved += 1;
+        }
+
+        num_solved
     }
 
     fn ask_tower(&self, msg: &str) -> io::Result<Input> {
@@ -477,10 +676,14 @@ impl GameGenerator {
 impl<const TOWER_HEIGHT: usize> Display for Game<TOWER_HEIGHT> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         for i in (0..TOWER_HEIGHT).rev() {
-            for _ in 0..3 {
+            for m in 0..3 {
                 for t in &self.towers {
                     if let Some(r) = t.rings[i] {
+                        if m == 1 {
+                            write!(f, "   {r:#}   ")?;
+                        } else {
                             write!(f, "   {r:}   ")?;
+                        }
                     } else {
                         write!(f, "             ")?;
                     }
@@ -499,6 +702,11 @@ impl<const TOWER_HEIGHT: usize> Display for Game<TOWER_HEIGHT> {
             let num = format!(" {} ", t + 1);
             write!(f, "{num:━^13}")?;
         }
+        writeln!(f)?;
+        for t in 0..self.towers.len() {
+            let num = format!(" {} ", self.towers[t].burried_score());
+            write!(f, "{num:^13}")?;
+        }
 
         Ok(())
     }
@@ -534,13 +742,27 @@ impl<const TOWER_HEIGHT: usize> UndoStack<TOWER_HEIGHT> {
 fn main() -> io::Result<()> {
     let mut g = GameGenerator {
         num_extra_towers: 2,
-        num_ring_types: 8,
+        num_ring_types: 12,
     }
     .generate::<4>();
 
+    if let Some(solution) = g.solve() {
+        let mut g = Game {
+            towers: g.towers.clone(),
+            ring_sets: g.ring_sets.clone(),
+        };
+        for i in solution {
             println!("{CLEAR_SCREEN}");
-    let mut u = UndoStack::new();
-    while let ControlFlow::Continue(()) = g.cli_move(&mut u)? {}
+            g.make_move(i).unwrap();
+            println!("{g}");
+            stdout().flush().unwrap();
+            stdin().read_line(&mut String::new()).unwrap();
+        }
+    }
+
+    // println!("{CLEAR_SCREEN}");
+    // let mut u = UndoStack::new();
+    // while let ControlFlow::Continue(()) = g.cli_move(&mut u)? {}
 
     Ok(())
 }