From 44db744ae30f5f911b9f4ec46b81668bdb6a1694 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maximilian=20Ke=C3=9Fler?= <git@maximilian-kessler.de>
Date: Thu, 10 Aug 2023 18:27:25 +0200
Subject: [PATCH] refactor backtracking function

---
 game_state.h   | 4 ++--
 game_state.hpp | 8 ++++----
 main.cpp       | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/game_state.h b/game_state.h
index 1186547..2c0f366 100644
--- a/game_state.h
+++ b/game_state.h
@@ -173,7 +173,7 @@ struct BacktrackAction {
 
 class HanabiStateIF {
 public:
-    virtual probability_t backtrack(size_t depth) = 0;
+    virtual probability_t evaluate_state() = 0;
 
     virtual void clue() = 0;
     virtual void discard(hand_index_t index) = 0;
@@ -203,7 +203,7 @@ public:
     HanabiState() = default;
     explicit HanabiState(const std::vector<Card>& deck);
 
-    probability_t backtrack(size_t depth) final;
+    probability_t evaluate_state() final;
 
     void clue() final;
     void play(hand_index_t index) final;
diff --git a/game_state.hpp b/game_state.hpp
index eec2c92..58a1baa 100644
--- a/game_state.hpp
+++ b/game_state.hpp
@@ -437,7 +437,7 @@ namespace Hanabi {
 
 
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
-    probability_t HanabiState<num_suits, num_players, hand_size>::backtrack(size_t depth) {
+    probability_t HanabiState<num_suits, num_players, hand_size>::evaluate_state() {
         _enumerated_states++;
         const unsigned long id_of_state = unique_id();
 
@@ -462,7 +462,7 @@ namespace Hanabi {
                 probability_t sum_of_probabilities = 0;
 
                 do_for_each_potential_draw<true>(index, [this, &sum_of_probabilities](const unsigned long multiplicity){
-                    sum_of_probabilities += backtrack(0) * multiplicity;
+                    sum_of_probabilities += evaluate_state() * multiplicity;
                 });
 
                 const unsigned long total_weight = std::max(static_cast<unsigned long>(_weighted_draw_pile_size), 1ul);
@@ -483,7 +483,7 @@ namespace Hanabi {
                     probability_t sum_of_probabilities = 0;
 
                     do_for_each_potential_draw<false>(index, [this, &sum_of_probabilities](const unsigned long multiplicity){
-                        sum_of_probabilities += backtrack(0) * multiplicity;
+                        sum_of_probabilities += evaluate_state() * multiplicity;
                     });
 
                     const unsigned long total_weight = std::max(static_cast<unsigned long>(_weighted_draw_pile_size), 1ul);
@@ -505,7 +505,7 @@ namespace Hanabi {
         // Last option is to stall
         if(_num_clues > 0) {
             clue();
-            const probability_t probability_stall = backtrack(depth + 1);
+            const probability_t probability_stall = evaluate_state();
             revert_clue();
             best_probability = std::max(best_probability, probability_stall);
             if (best_probability == 1) {
diff --git a/main.cpp b/main.cpp
index f17545f..8b8c316 100644
--- a/main.cpp
+++ b/main.cpp
@@ -17,7 +17,7 @@ namespace Hanabi {
     void download(std::variant<int, const char*> game_id, int turn) {
         auto game = Download::get_game(game_id, turn);
         std::cout << "Analysing state: " << std::endl << *game << std::endl;
-        auto res = game->backtrack(1);
+        auto res = game->evaluate_state();
         std::cout.precision(10);
         std::cout << std::endl;
         std::cout << "Probability with optimal play: " << res << std::endl;
@@ -52,7 +52,7 @@ namespace Hanabi {
 void test() {
     {
         auto game = Download::get_game("in/1005195", 43);
-        auto res = game->backtrack(1);
+        auto res = game->evaluate_state();
         CHECK("1005195", res == Hanabi::probability_t (7,8));
     }
 }
@@ -68,7 +68,7 @@ void check_games(unsigned num_players, unsigned max_draw_pile_size, unsigned fir
         for(size_t game_id = first_game; game_id <= last_game; game_id++) {
             const std::string input_fname = "json/" + std::to_string(num_players) + "p/" + std::to_string(game_id) + ".json";
             auto game = Download::get_game(input_fname.c_str(), 50, draw_pile_size);
-            const Hanabi::probability_t chance = game->backtrack(0);
+            const Hanabi::probability_t chance = game->evaluate_state();
             winning_percentages[game_id].push_back(chance);
             if(chance != 1) {
                 file << "Game " << game_id << ": " << chance << std::endl;