Added minion order optimization

src/battle.cpp

@@ -47,7 +47,7 @@ void Battle::single_attack_by(int player, int from) {
   Board& enemy = board[1-player];
   int target = attacker.type == MinionType::ZappSlywick
                  ? enemy.lowest_attack_target() : enemy.random_attack_target();
-  if (verbose) {
+  if (verbose && log) {
     *log << "attack by " << player << "." << from << ", " << attacker << (cleave ? "[C]" : "") << " to " << target << endl;
   }
   // Make a snapshot of the defending minion, so we know attack values
@@ -96,7 +96,7 @@ void Battle::on_after_friendly_attack(Minion const& attacker, int player) {
 bool Battle::damage(int player, int pos, int amount, bool poison) {
   if (amount <= 0) return false;
   Minion& m = board[player].minions[pos];
-  if (verbose >= 2) {
+  if (verbose >= 2 && log) {
     *log << "damage of " << amount << (poison ? "[P]" : "") << " to " << player << "." << pos << ", " << m << endl;
   }
   if (m.divine_shield) {
@@ -115,7 +115,7 @@ bool Battle::damage(int player, int pos, int amount, bool poison) {
 }
 
 bool Battle::damage(Minion const& attacker, int player, int pos) {
-  if (verbose >= 4) {
+  if (verbose >= 4 && log) {
     *log << "damage by " << attacker << " to " << player << "." << pos << endl;
   }
   return damage(player, pos, attacker.attack, attacker.poison);
@@ -205,7 +205,7 @@ void Battle::destroy_minion(int player, int pos) {
 */
 
 void Battle::on_death(Minion const& dead_minion, int player, int pos) {
-  if (verbose) {
+  if (verbose && log) {
     *log << "death: " << dead_minion << " at " << player << "." << pos << endl;
   }
   do_deathrattle(dead_minion, player, pos);
@@ -275,7 +275,7 @@ void Battle::on_summoned(Minion& summoned, int player) {
 void Battle::do_hero_powers() {
   for (int player=0; player<2; ++player) {
     HeroPower& hp = board[player].hero_power;
-    if (verbose >= 2 && hp != HeroPower::None) {
+    if (verbose >= 2 && log && hp != HeroPower::None) {
       *log << "Hero power " << hp << " for " << player << endl;
     }
     do_hero_power(hp, player);

src/battle.hpp

@@ -21,8 +21,8 @@ struct Battle {
   int verbose = 0;
   ostream* log;
 
-  Battle(ostream* log = &std::cout) : log(log) {}
-  Battle(Board const& b0, Board const& b1, ostream* log = &std::cout) : board{b0,b1}, log(log) {
+  Battle(ostream* log = nullptr) : log(log) {}
+  Battle(Board const& b0, Board const& b1, ostream* log = nullptr) : board{b0,b1}, log(log) {
     recompute_auras();
   }
 

src/repl.cpp

@@ -59,6 +59,7 @@ struct REPL {
   void do_help();
   void do_quit();
   void do_board(int player);
+  void do_swap();
   void do_show();
   void do_reset();
   void do_step();
@@ -67,6 +68,7 @@ struct REPL {
   void do_list_minions();
   void do_list_hero_powers();
   void do_run(int runs = -1);
+  void do_optimize_order(int runs = -1);
   void do_add_minion(Minion const&);
   void do_end_input();
 };
@@ -257,6 +259,8 @@ void REPL::parse_line(std::string const& line) {
     do_board(0);
   } else if (cmd == "vs") {
     do_board(1);
+  } else if (cmd == "swap") {
+    do_swap();
   } else if (cmd == "info" || cmd == "msg" || cmd == "message" || cmd == "print" || cmd == "echo") {
     std::string msg;
     getline(in,msg);
@@ -277,6 +281,8 @@ void REPL::parse_line(std::string const& line) {
     int n = -1;
     in >> n;
     do_run(n);
+  } else if (cmd == "optimize") {
+    do_optimize_order();
   } else if (cmd == "runs") {
     int n = DEFAULT_NUM_RUNS;
     if (in >> n && n > 0) {
@@ -411,7 +417,7 @@ void REPL::do_help() {
   out << "-- Running simulations" << endl;
   out << "actual <i> = tell about actual outcome (used in simulation display)" << endl;
   out << "run [<n>]  = run n simulations (default: 100)" << endl;
-  //out << "optimize   = optimize the minion order to maximize win%" << endl;
+  out << "optimize   = optimize the minion order to maximize winrate" << endl;
   out << endl;
   out << "-- Stepping through a single battle" << endl;
   out << "show       = show the board state" << endl;
@@ -464,6 +470,10 @@ void REPL::do_board(int player) {
   used = false;
 }
 
+void REPL::do_swap() {
+  std::swap(players[0], players[1]);
+}
+
 void REPL::do_add_minion(Minion const& m) {
   if (players[current_player].full()) {
     error() << "Player already has a full board" << endl;
@@ -511,7 +521,7 @@ void print_damage_taken(ostream& out, int enemy_level, int health, vector<int> c
 
 void REPL::do_run(int n) {
   if (n <= 0) n = default_num_runs;
-  vector<int> results = simulate(Battle(players[0], players[1], &out), n);
+  vector<int> results = simulate(Battle(players[0], players[1]), n);
   out << "--------------------------------" << endl;
   print_stats(out, results);
   for (int o : actual_outcomes) {
@@ -523,6 +533,23 @@ void REPL::do_run(int n) {
   used = true;
 }
 
+void REPL::do_optimize_order(int n) {
+  if (n <= 0) n = default_num_runs;
+  OptimizeMinionOrder opt(players[0], players[1], n);
+  if (opt.current_score >= opt.best_score) {
+    out << "Your winrate cannot be improved by reordering your minions" << endl;
+  } else {
+    out.precision(1);
+    out.setf(std::ios::fixed, std:: ios::floatfield);
+    out << "Your winrate can be improved from " << 100*opt.current_score << "% to " << 100*opt.best_score << "% by reordering your minions:" << endl;
+    Board new_board = players[0];
+    permute_minions(new_board, players[0].minions, opt.best_order.data(), opt.n);
+    out << new_board;
+    // TODO: significance test
+  }
+  used = true;
+}
+
 void REPL::do_show() {
   if (!battle_started) {
     step_battle = Battle(players[0], players[1], &out);

src/simulation.hpp

@@ -1,5 +1,6 @@
 #include "battle.hpp"
 #include <vector>
+#include <array>
 #include <algorithm>
 using std::vector;
 
@@ -109,4 +110,41 @@ int percentile(int i, vector<int> const& results) {
 // Optimization
 // -----------------------------------------------------------------------------
 
+void permute_minions(Board& board, Minion const original[], int const perm[], int n) {
+  // note: original != board.minions
+  for (int i=0; i<n; ++i) {
+    board.minions[i] = original[perm[i]];
+  }
+}
+
+struct OptimizeMinionOrder {
+  std::array<int,BOARDSIZE> best_order;
+  double current_score;
+  double best_score;
+  int n;
+
+  OptimizeMinionOrder(Board const& board, Board const& enemy, int runs = DEFAULT_NUM_RUNS) {
+    n = board.size();
+    // current situation
+    std::array<int,BOARDSIZE> order;
+    for (int i=0; i<n; ++i) order[i] = i;
+    // optimize
+    bool current = true;
+    do {
+      // check
+      Battle battle(board, enemy);
+      permute_minions(battle.board[0], board.minions, order.data(), n);
+      double score = simulate_optimization_score(battle, runs);
+      if (current) { // first permutation = current situation
+        current = false;
+        current_score = score;
+        best_score = score;
+        best_order = order;
+      } else if (score > best_score) {
+        best_score = score;
+        best_order = order;
+      }
+    } while (std::next_permutation(order.begin(), order.begin() + n));
+  }
+};
 

web/index.html

@@ -10,9 +10,6 @@
         var out = document.getElementById("output");
         out.textContent = Module.run(input.value + "\n" + cmd);
       }
-      function do_trace() {
-        do_run("trace");
-      }
       function do_help(cmd="help") {
         var out = document.getElementById("output");
         out.textContent = Module.run(cmd);
@@ -58,8 +55,9 @@ <h1>Hearthstone Battlegrounds Battle Simulator</h1>
 </textarea>
 </div>
 <div>
-  <button class="btn btn-primary" onclick="do_run();">Simulate</button>
-  <button class="btn btn-primary" onclick="do_trace();">Trace</button>
+  <button class="btn btn-primary" onclick="do_run();" title="Run the battle many times">Simulate</button>
+  <button class="btn btn-primary" onclick="do_run('optimize');" title="Reorder minions to optimize winrate">Optimize order</button>
+  <button class="btn btn-primary" onclick="do_run('trace');">Trace</button>
   <button class="btn btn-info" onclick="do_help('minions');">List of minions</button>
   <button class="btn btn-info" onclick="do_help();">Help</button>
 </div>