test 10

2019/10.cpp

@@ -1,9 +1,12 @@
 #include <algorithm>
 #include <iostream>
-#include <utility>
+#include <map>
 #include <numeric>
 #include <set>
-#include <map>
+#include <sstream>
+#include <utility>
+
+#include <doctest.h>
 
 #include <aocpp/Startup.hpp>
 #include <aocpp/Coord.hpp>
@@ -87,7 +90,7 @@ auto Part1(Grid const& grid) {
   return std::make_pair(best, base);
 }
 
-auto Part2(Grid const& grid, Coord base) {
+auto Part2(Grid const& grid, Coord base, std::size_t n) {
   std::map<Rational<std::int64_t>, std::vector<Coord>> targets;
 
   // arrange all the other asteroids by their angle relative to the base
@@ -107,7 +110,7 @@ auto Part2(Grid const& grid, Coord base) {
 
   // Remove 199 asteroids from the asteroid list
   auto cursor = targets.begin();
-  for (std::size_t n = 199; n > 0; n--) {
+  for (; n > 1; n--) {
     if (targets.empty()) { throw std::runtime_error{"no solution to part 2"}; }
 
     cursor->second.pop_back();
@@ -129,9 +132,85 @@ auto Part2(Grid const& grid, Coord base) {
 
 } // namespace
 
+TEST_SUITE("documented examples") {
+
+  char const* bigexample =
+    ".#..##.###...#######\n"
+    "##.############..##.\n"
+    ".#.######.########.#\n"
+    ".###.#######.####.#.\n"
+    "#####.##.#.##.###.##\n"
+    "..#####..#.#########\n"
+    "####################\n"
+    "#.####....###.#.#.##\n"
+    "##.#################\n"
+    "#####.##.###..####..\n"
+    "..######..##.#######\n"
+    "####.##.####...##..#\n"
+    ".#####..#.######.###\n"
+    "##...#.##########...\n"
+    "#.##########.#######\n"
+    ".####.#.###.###.#.##\n"
+    "....##.##.###..#####\n"
+    ".#.#.###########.###\n"
+    "#.#.#.#####.####.###\n"
+    "###.##.####.##.#..##\n";
+
+  TEST_CASE("part 1") {
+    auto test = [](Coord base, std::size_t count, std::string text) {
+      std::istringstream in {std::move(text)};
+      auto [count_, base_] = Part1(Grid::Parse(in));
+      REQUIRE(count_ == count);
+      REQUIRE(base_ == base);
+    };
+    test({3,4}, 8,
+      ".#..#\n"
+      ".....\n"
+      "#####\n"
+      "....#\n"
+      "...##\n");
+    test({1,2}, 35,
+      "#.#...#.#.\n"
+      ".###....#.\n"
+      ".#....#...\n"
+      "##.#.#.#.#\n"
+      "....#.#.#.\n"
+      ".##..###.#\n"
+      "..#...##..\n"
+      "..##....##\n"
+      "......#...\n"
+      ".####.###.\n");
+    test({6,3}, 41,
+      ".#..#..###\n"
+      "####.###.#\n"
+      "....###.#.\n"
+      "..###.##.#\n"
+      "##.##.#.#.\n"
+      "....###..#\n"
+      "..#.#..#.#\n"
+      "#..#.#.###\n"
+      ".##...##.#\n"
+      ".....#.#..\n");
+    test({11,13}, 210, bigexample);
+  }
+  TEST_CASE("part 2") {
+    auto test = [](std::size_t answer, Coord base, std::size_t nth, std::string text) {
+      std::istringstream in {std::move(text)};
+      REQUIRE(answer == Part2(Grid::Parse(in), base, nth));
+    };
+    test(1403, {8,3}, 36,
+      ".#....#####...#..\n"
+      "##...##.#####..##\n"
+      "##...#...#.#####.\n"
+      "..#.....X...###..\n"
+      "..#.#.....#....##\n");
+    test(802, {11,13}, 200, bigexample);
+  }
+}
+
 auto main(int argc, char** argv) -> int {
   auto grid = Grid::Parse(Startup(argc, argv));
   auto [part1, base] = Part1(grid);
   std::cout << "Part 1: " << part1 << std::endl;
-  std::cout << "Part 2: " << Part2(grid, base) << std::endl;
+  std::cout << "Part 2: " << Part2(grid, base, 200) << std::endl;
 }