1 files changed, 80 insertions, 4 deletions

diff --git a/2015/src/day22.cpp b/2015/src/day22.cpp
index 85b7259..b7a23d0 100644
--- a/2015/src/day22.cpp
+++ b/2015/src/day22.cpp
@@ -17,8 +17,8 @@ auto& debug = cerr;
 struct NullBuffer : streambuf {
         int overflow(int chr) override { return chr; }
 };
-NullBuffer nullBuffer;
-ostream    debug{ &nullBuffer };
+NullBuffer nullBuffer;           // NOLINT
+ostream    debug{ &nullBuffer }; // NOLINT
 #endif
 
 using Mana      = int;
@@ -121,6 +121,7 @@ public:
         }
 
         Mana      mana_;
+        Mana      mana_bought_{};
         HitPoints hit_points_;
         Armor     armor_{};
 };
@@ -133,6 +134,7 @@ public:
         {
                 debug << "Player casts " << spell->name_ << endl;
                 player.SubMana(spell->mana_);
+                player.mana_bought_ += spell->mana_;
 
                 if ( spell->Timer() == 0 ) {
                         spell->Play(player, boos);
@@ -142,7 +144,7 @@ public:
                 }
         }
 
-        bool TryAddRandomSpell(Player& player, Boss& boss)
+        [[nodiscard]] bool TryAddRandomSpell(Player& player, Boss& boss)
         {
                 while ( true ) {
                         auto randomSpell = chooseRandomSpell(player);
@@ -156,6 +158,8 @@ public:
                         }
 
                         AddSpell(randomSpell, player, boss);
+
+                        return true;
                 }
         }
 
@@ -553,8 +557,80 @@ battle2()
         cout << "End of Battle" << endl;
 }
 
+enum RoundState {
+        Player_Lost,
+        Boss_Lost,
+        Undecided
+};
+
+RoundState
+battle_round(Player& player, Boss& boss, Spells& spells)
+{
+        debug << "\n-- Player turn --\n"
+              << player << '\n'
+              << boss << endl;
+
+        spells.Play(player, boss);
+        if ( player.HasLost() ) {
+                return Player_Lost;
+        }
+        if ( boss.HasLost() ) {
+                return Boss_Lost;
+        }
+        if ( !spells.TryAddRandomSpell(player, boss) ) {
+                return Player_Lost;
+        }
+
+        // ----------------------
+
+        debug << "\n-- Boss turn --\n"
+              << player << '\n'
+              << boss << endl;
+
+        spells.Play(player, boss);
+        if ( player.HasLost() ) {
+                return Player_Lost;
+        }
+        if ( boss.HasLost() ) {
+                return Boss_Lost;
+        }
+        boss.Play(player);
+        if ( player.HasLost() ) {
+                return Player_Lost;
+        }
+        return Undecided;
+}
+
+void
+part1()
+{
+        const Boss boss_master("data/day22.txt");
+
+        static const Mana      start_mana      = 500;
+        static const HitPoints start_hitpoints = 50;
+
+        auto min_mana{ 999999 };
+
+        for ( int i = 0; i != 500000; ++i ) {
+                Boss   boss{ boss_master };
+                Player player(start_mana, start_hitpoints);
+                Spells spells;
+
+                auto roundState = battle_round(player, boss, spells);
+                while ( roundState == Undecided ) {
+                        roundState = battle_round(player, boss, spells);
+                }
+
+                if ( roundState == Boss_Lost ) {
+                        min_mana = min(min_mana, player.mana_bought_);
+                }
+        }
+        cout << min_mana << endl;
+}
+
 int
 main()
 {
-        battle2();
+        srand((unsigned int) time(NULL));
+        part1();
 }