Implement day 13 part 2.

2019/CMakeLists.txt

@@ -4,10 +4,16 @@ project(aoc2019)
 
 find_package(GTest REQUIRED)
 
+option(ANIMATE_DAY13 "Animate the Arkanoid game in day 13." Off)
+
 file(GLOB DAYS_FILES src/day*.cpp)
 add_library(AoCSolutions src/implementations.cpp "${DAYS_FILES}" src/point.hpp src/utils.cpp src/utils.hpp)
 target_compile_features(AoCSolutions PUBLIC cxx_std_17)
 
+if (ANIMATE_DAY13)
+    target_compile_definitions(AoCSolutions ANIMATE_DAY13)
+endif ()
+
 add_executable(runner src/runner.cpp)
 target_compile_features(runner PUBLIC cxx_std_17)
 target_link_libraries(runner AoCSolutions)

2019/src/day13.cpp

@@ -1,4 +1,8 @@
 #include <iostream>
+#ifdef ANIMATE_DAY13
+#include <chrono>
+#include <thread>
+#endif
 #include "days.hpp"
 #include "utils.hpp"
 #include "point.hpp"
@@ -13,28 +17,128 @@ namespace {
         PADDLE,
         BALL,
     };
+
+    typedef std::unordered_map<point_t, Tile> Screen;
+
+    std::optional<std::int64_t> update_screen(std::deque<std::int64_t> &output_buffer, Screen &screen) {
+        std::optional<std::int64_t> score;
+        while (!output_buffer.empty()) {
+            auto x = output_buffer.front(); output_buffer.pop_front();
+            auto y = output_buffer.front(); output_buffer.pop_front();
+            auto type = output_buffer.front(); output_buffer.pop_front();
+
+            if (x == -1 && y == 0) {
+                score = type;
+                continue;
+            }
+
+            screen[{x, y}] = static_cast<Tile>(type);
+        }
+        return score;
+    }
+
+    void draw_screen(const Screen &screen, std::ostream& output) {
+        // Determine bounding box
+        using limits = std::numeric_limits<int>;
+
+        std::int64_t left_edge = limits::max(), right_edge = limits::min(), top_edge = limits::max(), bottom_edge = limits::min();
+        for (auto& entry : screen) {
+            left_edge = std::min(entry.first[0], left_edge);
+            right_edge = std::max(entry.first[0], right_edge);
+            top_edge = std::min(entry.first[1], top_edge);
+            bottom_edge = std::max(entry.first[1], bottom_edge);
+        }
+
+        for (auto y = top_edge; y <= bottom_edge; ++y) {
+            for (auto x = left_edge; x <= right_edge; ++x) {
+                char c = ' ';
+                if (auto it = screen.find({x, y}); it != screen.end()) {
+                    switch (it->second) {
+                        case Tile::EMPTY:
+                            c = ' ';
+                            break;
+
+                        case Tile::BALL:
+                            c = '*';
+                            break;
+
+                        case Tile::BLOCK:
+                            c = '=';
+                            break;
+
+                        case Tile::PADDLE:
+                            c = '_';
+                            break;
+
+                        case Tile::WALL:
+                            c = '#';
+                            break;
+                    }
+                }
+
+                output << c;
+            }
+
+            output << '\n';
+        }
+    }
+
+    auto find_pos(const Screen &screen, Tile to_find) {
+        return std::find_if(screen.begin(), screen.end(), [to_find](const auto& x) {
+            return x.second == to_find;
+        });
+    }
 }
 
 void aoc2019::day13_part1(std::istream &input, std::ostream &output) {
+    Screen screen;
     aoc2019::IntCodeComputer computer(aoc2019::IntCodeComputer::read_intcode(input));
     std::deque<std::int64_t> output_buffer;
-
     computer.connectOutput(output_buffer);
     computer.run();
+    update_screen(output_buffer, screen);
 
-    std::unordered_map<point_t, Tile> drawn;
+    output << std::count_if(screen.begin(), screen.end(), [](const auto &x) { return x.second == Tile::BLOCK; })
-
+           << std::endl;
-    while (!output_buffer.empty()) {
-        auto x = output_buffer.front(); output_buffer.pop_front();
-        auto y = output_buffer.front(); output_buffer.pop_front();
-        auto type = output_buffer.front(); output_buffer.pop_front();
-
-        drawn[{x, y}] = static_cast<Tile>(type);
-    }
-
-	output << std::count_if(drawn.begin(), drawn.end(), [](const auto& x) { return x.second == Tile::BLOCK; })<< std::endl;
 }
 
 void aoc2019::day13_part2(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+    auto program = aoc2019::IntCodeComputer::read_intcode(input);
+    program[0] = 2;
+
+    aoc2019::IntCodeComputer computer(std::move(program));
+    std::deque<std::int64_t> output_buffer;
+    computer.connectOutput(output_buffer);
+    computer.run();
+
+    Screen screen;
+
+    std::int64_t score = 0;
+
+    while (!computer.isTerminated()) {
+        computer.run();
+        auto new_score = update_screen(output_buffer, screen);
+        if (new_score) {
+            score = *new_score;
+        }
+
+#ifdef ANIMATE_DAY13
+        output << "Score: " << score << std::endl;
+        draw_screen(screen, output);
+        std::this_thread::sleep_for(std::chrono::milliseconds(40));
+#endif
+
+        auto ball_pos = find_pos(screen, Tile::BALL)->first;
+        auto paddle_pos = find_pos(screen, Tile::PADDLE)->first;
+
+        if (ball_pos[0] < paddle_pos[0]) {
+            computer.sendInput(-1);
+        } else if (ball_pos[0] > paddle_pos[0]) {
+            computer.sendInput(1);
+        } else {
+            computer.sendInput(0);
+        }
+    }
+
+    output << score << std::endl;
 }