Add solution for 2025 Day 8

res/2025/day08/test_input.txt

@@ -0,0 +1,20 @@
+162,817,812
+57,618,57
+906,360,560
+592,479,940
+352,342,300
+466,668,158
+542,29,236
+431,825,988
+739,650,466
+52,470,668
+216,146,977
+819,987,18
+117,168,530
+805,96,715
+346,949,466
+970,615,88
+941,993,340
+862,61,35
+984,92,344
+425,690,689

src/2025/Day08.cpp

@@ -2,35 +2,114 @@
 
 namespace y2025::day08
 {
-  using InputType = std::vector<int>;
-  REGISTER_DAY(2025, Day08, InputType, int);
+  using InputType = std::vector<Index3D>;
+  REGISTER_DAY(2025, Day08, InputType, int64_t);
 
-  REGISTER_TEST_EXAMPLE(2025, Day08, ExampleInput, 1, 0);
-  REGISTER_TEST(2025, Day08, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2025, Day08, ExampleInput, 2, 0);
-  REGISTER_TEST(2025, Day08, Input, 2, 0);
+  REGISTER_TEST_EXAMPLE(2025, Day08, ExampleInput, 1, 40);
+  REGISTER_TEST(2025, Day08, Input, 1, 122636);
+  REGISTER_TEST_EXAMPLE(2025, Day08, ExampleInput, 2, 25272);
+  REGISTER_TEST(2025, Day08, Input, 2, 9271575747);
 
   READ_INPUT(input)
   {
-    std::vector<int> vec;
+    std::vector<Index3D> vec;
     std::string str;
     while (std::getline(input, str))
     {
       std::stringstream ss{str};
       int n;
-      ss >> n;
-      vec.emplace_back(n);
+      Index3D index;
+      ss >> index.x >> "," >> index.y >> "," >> index.z;
+      vec.emplace_back(index);
     }
     return vec;
   }
 
+  std::multimap<int64_t, std::pair<Index3D, Index3D>> CalculateDistances(const std::vector<Index3D>& indices)
+  {
+    std::multimap<int64_t, std::pair<Index3D, Index3D>> distances;
+    for (int i = 0; i < indices.size(); i++)
+    {
+      for (int j = i + 1; j < indices.size(); j++)
+      {
+        Index3D offset = indices[i] - indices[j];
+        int64_t distance = (int64_t)offset.x * (int64_t)offset.x + (int64_t)offset.y * (int64_t)offset.y +
+                           (int64_t)offset.z * (int64_t)offset.z;
+        distances.emplace(distance, std::pair{indices[i], indices[j]});
+      }
+    }
+    return distances;
+  }
+
+  void Connect(Index3D i1, Index3D i2, std::vector<std::set<Index3D>>& circuits)
+  {
+    int n1 = -1;
+    int n2 = -1;
+    for (int j = 0; j < circuits.size(); j++)
+    {
+      if (circuits[j].count(i1) != 0)
+        n1 = j;
+      if (circuits[j].count(i2) != 0)
+        n2 = j;
+      if (n1 != -1 && n2 != -1)
+        break;
+    }
+
+    if (n1 == -1 && n2 == -1)
+    {
+      circuits.emplace_back(std::set{i1, i2});
+    }
+    else if (n1 != -1 && n2 == -1)
+    {
+      circuits[n1].emplace(i2);
+    }
+    else if (n1 == -1 && n2 != -1)
+    {
+      circuits[n2].emplace(i1);
+    }
+    else if (n1 != -1 && n2 != -1 && n1 != n2)
+    {
+      std::set<Index3D> cpy = circuits[n2];
+      circuits[n1].insert(cpy.begin(), cpy.end());
+      circuits.erase(circuits.begin() + n2);
+    }
+  }
+
   OUTPUT1(input)
   {
-    return 0;
+    std::multimap<int64_t, std::pair<Index3D, Index3D>> distances = CalculateDistances(input);
+    std::vector<std::set<Index3D>> circuits;
+    auto it = distances.begin();
+    int count = isExample ? 10 : 1000;
+    for (int i = 0; i < count; i++, it++)
+    {
+      Connect(it->second.first, it->second.second, circuits);
+    }
+    std::sort(circuits.begin(),
+              circuits.end(),
+              [](const std::set<Index3D>& set1, const std::set<Index3D>& set2) { return set1.size() > set2.size(); });
+    int64_t product = 1;
+    for (int i = 0; i < 3; i++)
+    {
+      product *= circuits[i].size();
+    }
+    return product;
   }
 
   OUTPUT2(input)
   {
-    return 0;
+    std::multimap<int64_t, std::pair<Index3D, Index3D>> distances = CalculateDistances(input);
+    std::vector<std::set<Index3D>> circuits;
+    for (int i = 0; i < input.size(); i++)
+    {
+      circuits.emplace_back(std::set{input[i]});
+    }
+    auto it = distances.begin();
+    for (; circuits.size() != 1; it++)
+    {
+      Connect(it->second.first, it->second.second, circuits);
+    }
+    it--;
+    return (int64_t)it->second.first.x * (int64_t)it->second.second.x;
   }
 }