Initial commit with solutions from 2024

src/2024/Day19.cpp

@@ -0,0 +1,116 @@
+#include "common/aoc.h"
+
+namespace day19
+{
+  struct Towels
+  {
+    std::vector<std::string> patterns;
+    std::vector<std::string> towels;
+  };
+
+  REGISTER_DAY(2024, Day19, Towels, int64_t);
+
+  REGISTER_TEST_EXAMPLE(2024, Day19, ExampleInput, 1, 6);
+  REGISTER_TEST(2024, Day19, Input, 1, 353);
+  REGISTER_TEST_EXAMPLE(2024, Day19, ExampleInput, 2, 16);
+  REGISTER_TEST(2024, Day19, Input, 2, 880877787214477);
+
+  READ_INPUT(input)
+  {
+    Towels strings;
+    std::string str;
+    std::getline(input, str);
+    std::stringstream ss{str};
+    while (std::getline(ss, str, ','))
+    {
+      if (str.front() == ' ')
+        str = str.substr(1);
+      strings.patterns.emplace_back(str);
+    }
+
+    std::getline(input, str);
+
+    while (std::getline(input, str))
+    {
+      strings.towels.emplace_back(str);
+    }
+    return strings;
+  }
+
+  bool HasCombination(const std::string& towel,
+                      const std::vector<std::string>& patterns,
+                      int offset,
+                      std::set<int>& memoization)
+  {
+    if (offset == towel.size())
+      return true;
+
+    if (memoization.count(offset) != 0)
+      return false;
+
+    for (auto& other : patterns)
+    {
+      if (Helper::StartsWith(std::string_view(towel.c_str() + offset, towel.size() - offset), other))
+      {
+        if (HasCombination(towel, patterns, offset + other.size(), memoization))
+        {
+          return true;
+        }
+      }
+    }
+
+    memoization.emplace(offset);
+    return false;
+  }
+
+  int64_t AmountOfCombinations(const std::string& towel,
+                               const std::vector<std::string>& patterns,
+                               int offset,
+                               std::map<int, int64_t>& memoization)
+  {
+    if (offset == towel.size())
+      return 1;
+
+    auto it = memoization.find(offset);
+    if (it != memoization.end())
+      return it->second;
+
+    int64_t amount = 0;
+    for (auto& other : patterns)
+    {
+      if (Helper::StartsWith(std::string_view(towel.c_str() + offset, towel.size() - offset), other))
+      {
+        amount += AmountOfCombinations(towel, patterns, offset + other.size(), memoization);
+      }
+    }
+    memoization[offset] = amount;
+    return amount;
+  }
+
+  OUTPUT1(input)
+  {
+    int64_t sum = 0;
+
+    for (auto& towel : input.towels)
+    {
+      std::set<int> memoization;
+      if (HasCombination(towel, input.patterns, 0, memoization))
+        sum++;
+    }
+
+    return sum;
+  }
+
+  OUTPUT2(input)
+  {
+    int64_t sum = 0;
+
+    for (auto& towel : input.towels)
+    {
+      std::map<int, int64_t> memoization;
+      sum += AmountOfCombinations(towel, input.patterns, 0, memoization);
+    }
+
+    return sum;
+  }
+}