Add solution for 2016 Day 15

src/2016/Day15.cpp

@@ -2,30 +2,57 @@
 
 namespace y2016::day15
 {
-  REGISTER_DAY(2016, Day15, std::vector<int>, int);
+  struct Disc
+  {
+    int positions;
+    int position;
+  };
 
-  REGISTER_TEST_EXAMPLE(2016, Day15, ExampleInput, 1, 0);
-  REGISTER_TEST(2016, Day15, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2016, Day15, ExampleInput, 2, 0);
-  REGISTER_TEST(2016, Day15, Input, 2, 0);
+  REGISTER_DAY(2016, Day15, std::vector<Disc>, int64_t);
+
+  REGISTER_TEST_EXAMPLE(2016, Day15, ExampleInput, 1, 25);
+  REGISTER_TEST(2016, Day15, Input, 1, 400589);
+  REGISTER_TEST_EXAMPLE(2016, Day15, ExampleInput, 2, 205);
+  REGISTER_TEST(2016, Day15, Input, 2, 3045959);
 
   READ_INPUT(input)
   {
-    std::vector<int> vec;
+    std::vector<Disc> vec;
     std::string str;
     while (getline(input, str))
     {
+      std::stringstream ss{str};
+      int i;
+      Disc disc;
+      ss >> "Disc #" >> i >> "has " >> disc.positions >> "positions; at time=" >> i >> ", it is at position " >>
+        disc.position;
+      vec.emplace_back(disc);
     }
     return vec;
   }
 
+  int64_t Solve(const std::vector<Disc>& discs)
+  {
+    std::vector<int64_t> starts;
+    std::vector<int64_t> mods;
+    std::vector<int64_t> remainders(discs.size(), 0);
+    for (int j = 0; j < discs.size(); j++)
+    {
+      starts.emplace_back(discs[j].position + j + 1);
+      mods.emplace_back(discs[j].positions);
+    }
+    return Helper::ChineseRemainderTheorem(mods, remainders, starts);
+  }
+
   OUTPUT1(input)
   {
-    return 0;
+    return Solve(input);
   }
 
   OUTPUT2(input)
   {
-    return 0;
+    auto discs = input;
+    discs.emplace_back(Disc{11, 0});
+    return Solve(discs);
   }
 }