Add solution for 2016 Day 19

src/2016/Day19.cpp

@@ -2,30 +2,68 @@
 
 namespace y2016::day19
 {
-  REGISTER_DAY(2016, Day19, std::vector<int>, int);
+  REGISTER_DAY(2016, Day19, int, int);
 
-  REGISTER_TEST_EXAMPLE(2016, Day19, ExampleInput, 1, 0);
-  REGISTER_TEST(2016, Day19, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2016, Day19, ExampleInput, 2, 0);
-  REGISTER_TEST(2016, Day19, Input, 2, 0);
+  REGISTER_TEST_EXAMPLE(2016, Day19, ExampleInput, 1, 3);
+  REGISTER_TEST(2016, Day19, Input, 1, 1842613);
+  REGISTER_TEST_EXAMPLE(2016, Day19, ExampleInput, 2, 2);
+  REGISTER_TEST(2016, Day19, Input, 2, 1424135);
 
   READ_INPUT(input)
   {
-    std::vector<int> vec;
-    std::string str;
-    while (getline(input, str))
-    {
-    }
-    return vec;
+    int i;
+    input >> i;
+    return i;
   }
 
   OUTPUT1(input)
   {
-    return 0;
+    std::vector<int> elves(input, 0);
+    for (int i = 0; i < input; i++)
+    {
+      elves[i] = i + 1;
+    }
+    int offset = 0;
+    while (elves.size() > 1)
+    {
+      std::vector<int> newElves;
+      for (int i = offset; i < elves.size(); i += 2)
+      {
+        newElves.emplace_back(elves[i]);
+      }
+      offset = (offset + (elves.size() % 2)) % 2;
+      elves = newElves;
+    }
+    return elves[0];
   }
 
   OUTPUT2(input)
   {
-    return 0;
+    std::deque<int> start;
+    std::deque<int> end;
+    for (int i = 0; i < input / 2; i++)
+    {
+      start.push_back(i + 1);
+    }
+    for (int i = input / 2; i < input; i++)
+    {
+      end.push_back(i + 1);
+    }
+
+    while (!start.empty())
+    {
+      end.pop_front();
+
+      end.push_back(start.front());
+      start.pop_front();
+
+      if (end.size() - start.size() == 2)
+      {
+        start.push_back(end.front());
+        end.pop_front();
+      }
+    }
+
+    return end.front();
   }
 }