improvements to cheating strategy

src/game.rs

@@ -30,7 +30,7 @@ pub fn get_count_for_value(value: &Value) -> usize {
 
 pub type Player = u32;
 
-#[derive(Debug,Clone,PartialEq)]
+#[derive(Debug,Clone,PartialEq,Eq,Hash)]
 pub struct Card {
     pub color: Color,
     pub value: Value,
@@ -520,10 +520,13 @@ pub struct GameStateView<'a> {
     pub board: &'a BoardState,
 }
 impl <'a> GameStateView<'a> {
-    pub fn has_card(&self, player: &Player, card: &Card) -> bool {
+    pub fn get_hand(&self, player: &Player) -> &Cards {
         assert!(self.player != *player, "Cannot query about your own cards!");
-        let state = self.other_player_states.get(player).unwrap();
-        for other_card in &state.hand {
+        &self.other_player_states.get(player).unwrap().hand
+    }
+
+    pub fn has_card(&self, player: &Player, card: &Card) -> bool {
+        for other_card in self.get_hand(player) {
             if *card == *other_card {
                 return true;
             }

src/simulator.rs

@@ -59,9 +59,12 @@ pub fn simulate_once<'a>(
         // TODO: do some stuff
         debug!("State:\n{}", game);
     }
-    game.score()
+    let score = game.score();
+    debug!("SCORED: {:?}", score);
+    score
 }
 
+// TODO: multithreaded
 pub fn simulate<'a>(
         opts: &GameOptions,
         strat_configs: &Vec<Box<StrategyConfig + 'a>>,
@@ -73,6 +76,7 @@ pub fn simulate<'a>(
     let mut non_perfect_seeds = Vec::new();
 
     let first_seed = first_seed_opt.unwrap_or(rand::thread_rng().next_u32());
+    info!("Initial seed: {}\n", first_seed);
     let mut histogram = HashMap::<Score, usize>::new();
     for i in 0..n_trials {
         if (i > 0) && (i % 1000 == 0) {
@@ -81,7 +85,6 @@ pub fn simulate<'a>(
         }
         let seed = first_seed + i;
         let score = simulate_once(&opts, strat_configs, Some(seed));
-        debug!("Scored: {:?}", score);
         let count = histogram.get(&score).unwrap_or(&0) + 1;
         histogram.insert(score, count);
         if score != 25 {

src/strategies/cheating.rs

@@ -1,6 +1,6 @@
 use std::rc::Rc;
 use std::cell::{RefCell};
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 
 use simulator::*;
 use game::*;
@@ -101,6 +101,35 @@ impl CheatingStrategy {
         // maybe value 5s more?
         5 + (5 - (card.value as i32))
     }
+
+    fn find_useless_card(&self, view: &GameStateView, hand: &Cards) -> Option<usize> {
+        let mut set: HashSet<Card> = HashSet::new();
+
+        for (i, card) in hand.iter().enumerate() {
+            if view.board.is_dead(card) {
+                return Some(i);
+            }
+            if set.contains(card) {
+                // found a duplicate card
+                return Some(i);
+            }
+            set.insert(card.clone());
+        }
+        return None
+    }
+
+    fn someone_else_can_play(&self, view: &GameStateView) -> bool {
+        for player in view.board.get_players() {
+            if player != self.me {
+                for card in view.get_hand(&player) {
+                    if view.board.is_playable(card) {
+                        return true;
+                    }
+                }
+            }
+        }
+        false
+    }
 }
 impl Strategy for CheatingStrategy {
     fn decide(&mut self, view: &GameStateView) -> TurnChoice {
@@ -120,24 +149,23 @@ impl Strategy for CheatingStrategy {
             // if view.board.deck_size() > 10 {
             if view.board.discard.cards.len() < 5 {
                 // if anything is totally useless, discard it
-                for (i, card) in my_cards.iter().enumerate() {
-                    if view.board.is_dead(card) {
-                        return TurnChoice::Discard(i);
-                    }
-                }
-            }
-
-            // it's unintuitive that hinting is better than
-            // discarding dead cards, but turns out true
-            if view.board.hints_remaining > 1 {
-                return self.throwaway_hint(view);
-            }
-            // if anything is totally useless, discard it
-            for (i, card) in my_cards.iter().enumerate() {
-                if view.board.is_dead(card) {
+                if let Some(i) = self.find_useless_card(view, my_cards) {
                     return TurnChoice::Discard(i);
                 }
             }
+
+            // hinting is better than discarding dead cards
+            // (probably because it stalls the deck-drawing).
+            if view.board.hints_remaining > 1 {
+                if self.someone_else_can_play(view) {
+                    return self.throwaway_hint(view);
+                }
+            }
+            // if anything is totally useless, discard it
+            if let Some(i) = self.find_useless_card(view, my_cards) {
+                return TurnChoice::Discard(i);
+            }
+
             // All cards are plausibly useful.
             // Play the best discardable card, according to the ordering induced by comparing
             //   (is in another hand, is dispensable, value)