2022-08

2022/08.cpp

@@ -0,0 +1,80 @@
+#include <algorithm>
+#include <cstdint>
+#include <functional>
+#include <iostream>
+#include <numeric>
+#include <sstream>
+#include <vector>
+
+#include <doctest.h>
+
+#include <aocpp/Grid.hpp>
+#include <aocpp/Coord.hpp>
+#include <aocpp/Startup.hpp>
+
+using namespace aocpp;
+
+namespace {
+
+using Dir = Coord(*)(Coord);
+Dir directions[4] {Up, Down, Left, Right};
+
+auto Part1(Grid const& grid) -> std::int64_t
+{
+  std::int64_t result {0};
+  grid.each([&](Coord const c, char const v) {
+    result += std::any_of(
+      std::begin(directions), std::end(directions),
+      [&](Dir const dir) {
+        for (auto x = dir(c); grid.contains(x); x = dir(x)) {
+          if (grid[x] >= v) { return false; }
+        }
+        return true;
+      });
+  });
+  return result;
+}
+
+auto Part2(Grid const& grid) -> std::int64_t
+{
+  std::int64_t result {0};
+  grid.each([&](Coord const c, char const v) {
+    auto score = std::transform_reduce(
+      std::begin(directions), std::end(directions),
+      std::int64_t{1},
+      std::multiplies(),
+      [&](Dir const dir) {
+        std::int64_t count {0};
+        for (auto x = dir(c); grid.contains(x); x = dir(x)) {
+          count++;
+          if (grid[x] >= v) break;
+        }
+        return count;
+      });
+    if (result < score) result = score;
+  });
+  return result;
+}
+
+} // namespace
+
+TEST_SUITE("2022-08 examples") {
+  TEST_CASE("example") {
+    std::istringstream in {
+      "30373\n"
+      "25512\n"
+      "65332\n"
+      "33549\n"
+      "35390\n"};
+    auto grid = aocpp::Grid::Parse(in);
+    CHECK(Part1(grid) == 21);
+    CHECK(Part2(grid) == 8);
+  }
+}
+
+auto main(int argc, char** argv) -> int
+{
+  auto grid = Grid::Parse(*aocpp::Startup(argc, argv));
+  std::cout << "Part 1: " << Part1(grid) << std::endl;
+  std::cout << "Part 2: " << Part2(grid) << std::endl;
+}

2022/CMakeLists.txt

@@ -7,6 +7,9 @@ target_link_libraries(2022_03 aocpp)
 add_executable(2022_04 04.cpp)
 target_link_libraries(2022_04 aocpp)
 
+add_executable(2022_08 08.cpp)
+target_link_libraries(2022_08 aocpp)
+
 add_executable(2022_12 12.cpp)
 target_link_libraries(2022_12 aocpp)