Add solution for 2016 Day 11

2026-08-22 14:33:45 +02:00
parent fc16b73a01
commit 5d44b9484f
3 changed files with 217 additions and 9 deletions
@@ -0,0 +1,4 @@
+The first floor contains a hydrogen-compatible microchip and a lithium-compatible microchip.
+The second floor contains a hydrogen generator.
+The third floor contains a lithium generator.
+The fourth floor contains nothing relevant.
@@ -2,30 +2,219 @@

 namespace y2016::day11
 {
-  REGISTER_DAY(2016, Day11, std::vector<int>, int);
+  struct Item
+  {
+    int floorPos;
+    bool generator;
+    int id;

-  REGISTER_TEST_EXAMPLE(2016, Day11, ExampleInput, 1, 0);
-  REGISTER_TEST(2016, Day11, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2016, Day11, ExampleInput, 2, 0);
-  REGISTER_TEST(2016, Day11, Input, 2, 0);
+    bool operator==(const Item& item) const
+    {
+      return floorPos == item.floorPos && id == item.id && generator == item.generator;
+    }
+  };
+
+  static int FLOORS = 4;
+
+  REGISTER_DAY(2016, Day11, std::vector<Item>, int);
+
+  REGISTER_TEST_EXAMPLE(2016, Day11, ExampleInput, 1, 11);
+  REGISTER_TEST(2016, Day11, Input, 1, 37);
+  REGISTER_TEST(2016, Day11, Input, 2, 61);
+
+  Item ParseItem(const std::string_view& str, int floorPos, std::map<std::string, int>& nameToId)
+  {
+    size_t posDash = str.find('-');
+    std::string name;
+    bool generator;
+    if (posDash == std::string::npos)
+    {
+      name = str.substr(0, str.find(' '));
+      generator = true;
+    }
+    else
+    {
+      name = str.substr(0, posDash);
+      generator = false;
+    }
+    auto it = nameToId.find(name);
+    if (it != nameToId.end())
+      return Item{floorPos, generator, it->second};
+    int size = nameToId.size();
+    nameToId[name] = size;
+
+    return Item{floorPos, generator, size};
+  }

  READ_INPUT(input)
  {
-    std::vector<int> vec;
+    std::vector<Item> vec;
    std::string str;
-    while (getline(input, str))
+    std::map<std::string, int> nameToId;
+    for (int i = 0; i < FLOORS; i++)
    {
+      getline(input, str);
+      std::vector<std::string_view> split = Helper::Split(str, " a ");
+      for (size_t j = 1; j < split.size(); j++)
+      {
+        vec.emplace_back(ParseItem(split[j], i, nameToId));
+      }
    }
    return vec;
  }

+  struct State
+  {
+    std::vector<Item> items;
+    int elevatorPos;
+
+    int amountOfPairs;
+
+    std::vector<std::pair<int, int>> GetPairs() const
+    {
+      // Convert the data to a format where the pairs of generator/microchip don't matter. All that matters are their
+      // positions
+      std::vector<std::pair<int, int>> pairs(amountOfPairs);
+      for (const auto& item : items)
+      {
+        if (item.generator)
+          pairs[item.id].first = item.floorPos;
+        else
+          pairs[item.id].second = item.floorPos;
+      }
+      std::sort(pairs.begin(), pairs.end());
+      return pairs;
+    }
+
+    bool operator<(const State& state) const
+    {
+      if (elevatorPos != state.elevatorPos)
+        return elevatorPos < state.elevatorPos;
+      return GetPairs() < state.GetPairs();
+    }
+  };
+
+  bool HasItem(const State& state, int floor, bool generator, int id)
+  {
+    return std::find(state.items.begin(), state.items.end(), Item{floor, generator, id}) != state.items.end();
+  }
+
+  bool IsValidState(const State& state)
+  {
+    for (int i = 0; i < FLOORS; i++)
+    {
+      bool hasChipNotConnected = false;
+      int generators = 0;
+      for (const auto& item : state.items)
+      {
+        if (item.floorPos != i)
+          continue;
+        if (item.generator)
+        {
+          generators++;
+          continue;
+        }
+
+        if (HasItem(state, i, true, item.id))
+          continue;
+        hasChipNotConnected = true;
+      }
+      if (hasChipNotConnected && generators > 0)
+      {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  std::vector<std::pair<int, State>> Branch(const std::vector<Item>& input, const State& state)
+  {
+    std::vector<std::pair<int, State>> branches;
+    for (int i = -1; i <= 1; i += 2)
+    {
+      if (state.elevatorPos + i < 0 || state.elevatorPos + i > 3)
+        continue;
+
+      State newState = state;
+      newState.elevatorPos += i;
+      for (auto& item : newState.items)
+      {
+        if (item.floorPos != state.elevatorPos)
+          continue;
+
+        item.floorPos = newState.elevatorPos;
+        if (IsValidState(newState))
+          branches.emplace_back(1, newState);
+        item.floorPos = state.elevatorPos;
+      }
+
+      for (size_t i = 0; i < newState.items.size(); i++)
+      {
+        if (newState.items[i].floorPos != state.elevatorPos)
+          continue;
+        newState.items[i].floorPos = newState.elevatorPos;
+
+        for (size_t j = i + 1; j < newState.items.size(); j++)
+        {
+          if (newState.items[j].floorPos != state.elevatorPos)
+            continue;
+          newState.items[j].floorPos = newState.elevatorPos;
+          if (IsValidState(newState))
+            branches.emplace_back(1, newState);
+          newState.items[j].floorPos = state.elevatorPos;
+        }
+        newState.items[i].floorPos = state.elevatorPos;
+      }
+    }
+    return branches;
+  }
+
+  bool Goal(const std::vector<Item>& input, const State& state)
+  {
+    for (size_t i = 0; i < state.items.size(); i++)
+    {
+      if (state.items[i].floorPos != 3)
+        return false;
+    }
+    return true;
+  }
+
+  int Heuristic(const std::vector<Item>& input, const State& state)
+  {
+    int heuristic = 0;
+    int moves = 0;
+    for (size_t i = 0; i < state.items.size(); i++)
+    {
+      moves += (3 - state.items[i].floorPos);
+    }
+    heuristic += moves / 2;
+    return heuristic;
+  }
+
  OUTPUT1(input)
  {
-    return 0;
+    int max = 0;
+    for (const auto& item : input)
+    {
+      max = std::max(max, item.id);
+    }
+    State state{input, 0, max + 1};
+    return Helper::AStar(input, state, Heuristic, Branch, Goal);
  }

  OUTPUT2(input)
  {
-    return 0;
+    std::vector<Item> items = input;
+    int max = 0;
+    for (const auto& item : items)
+    {
+      max = std::max(max, item.id);
+    }
+    items.emplace_back(Item{0, true, max + 1});
+    items.emplace_back(Item{0, false, max + 1});
+    items.emplace_back(Item{0, true, max + 2});
+    items.emplace_back(Item{0, false, max + 2});
+    State state{items, 0, max + 3};
+    return Helper::AStar(input, state, Heuristic, Branch, Goal);
  }
 }
@@ -51,6 +51,21 @@ struct Helper
    t.erase(std::remove_if(t.begin(), t.end(), func), t.end());
  }

+  static std::vector<std::string_view> Split(const std::string& str, const std::string& delim)
+  {
+    std::vector<std::string_view> split;
+    size_t pos = str.find(delim);
+    size_t lastPos = 0;
+    while (pos != std::string::npos)
+    {
+      split.emplace_back(std::string_view{str.c_str() + lastPos, pos - lastPos});
+      lastPos = pos + delim.size();
+      pos = str.find(delim, pos + delim.size());
+    }
+    split.emplace_back(std::string_view{str.c_str() + lastPos, str.size() - lastPos});
+    return split;
+  }
+
  static bool StartsWith(const std::string_view& str, const std::string& prefix, size_t offset = 0)
  {
    return str.substr(offset, prefix.size()) == prefix;