day 8 (#25)

day_6/src/main.cpp

@@ -1,13 +1,14 @@
-#include "../../shared/src/exit_code.hpp"
-#include "../../shared/src/file_operations.hpp"
-#include "../../shared/src/grid_processor.hpp"
-#include "../../shared/src/print_compatibility_layer.hpp"
 #include <algorithm>
 #include <atomic>
 #include <execution>
 #include <numeric>
 #include <string>
 
+#include "../../shared/src/exit_code.hpp"
+#include "../../shared/src/file_operations.hpp"
+#include "../../shared/src/grid_processor.hpp"
+#include "../../shared/src/print_compatibility_layer.hpp"
+
 #include "../lib/grid_parser.hpp"
 #include "../lib/puzzle_map.hpp"
 

day_8/CMakeLists.txt

@@ -0,0 +1 @@
+aoc_day(8)

day_8/lib/CMakeLists.txt

@@ -0,0 +1 @@
+aoc_add_library()

day_8/lib/antinodes.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <map>
+#include <ranges>
+#include <string>
+#include <unordered_set>
+#include <vector>
+
+#include "../lib/coordinate.hpp"
+
+#include "../../shared/src/ranges_compatibility_layer.hpp"
+
+namespace aoc::day_8 {
+
+namespace detail {
+[[nodiscard]] static auto getOtherAntennaPositionsByFrequency(char frequency, coordinate const & exclude_pos,
+                                                              std::multimap<char, coordinate> const & antenas) {
+    auto range = antenas.equal_range(frequency);
+    return std::ranges::subrange(range.first, range.second) |
+           std::views::transform([](auto const & pair) { return pair.second; }) |
+           std::views::filter([&exclude_pos](coordinate const & pos) { return pos != exclude_pos; }) |
+           std::views::common;
+}
+
+[[nodiscard]] static auto generateAntinodeSequence(coordinate start, coordinate diff, int64_t max_x, int64_t max_y) {
+    return std::views::iota(0) | std::views::transform([=](int64_t i) { return start + diff * i; }) |
+           std::views::take_while([=](coordinate pos) { return pos.inBounds(max_x, max_y); });
+}
+} // namespace detail
+
+[[nodiscard]] auto determineAntinodes(int64_t max_x_coordinate, int64_t max_y_coordinate,
+                                      std::multimap<char, coordinate> const & antenas)
+    -> std::unordered_set<coordinate> {
+    return std::views::transform(
+               antenas,
+               [&](auto const & entry) {
+                   return detail::getOtherAntennaPositionsByFrequency(entry.first, entry.second, antenas) |
+                          std::views::transform([&entry](coordinate const & other_pos) {
+                              coordinate diff = other_pos - entry.second;
+                              return other_pos + diff;
+                          }) |
+                          std::views::filter([max_x_coordinate, max_y_coordinate](coordinate const & pos) {
+                              return pos.inBounds(max_x_coordinate, max_y_coordinate);
+                          });
+               }) |
+           std::views::join | aoc::ranges::to<std::unordered_set<coordinate>>;
+}
+
+[[nodiscard]] auto determineAntinodes2(int64_t max_x_coordinate, int64_t max_y_coordinate,
+                                       std::multimap<char, coordinate> const & antenas)
+    -> std::unordered_set<coordinate> {
+    return std::views::transform(
+               antenas,
+               [max_x = max_x_coordinate, max_y = max_y_coordinate, antenas = antenas](auto const & entry) {
+                   return detail::getOtherAntennaPositionsByFrequency(entry.first, entry.second, antenas) |
+                          std::views::transform([start = entry.second, max_x, max_y](coordinate const & other_pos) {
+                              return detail::generateAntinodeSequence(other_pos, other_pos - start, max_x, max_y);
+                          }) |
+                          std::views::join;
+               }) |
+           std::views::join | aoc::ranges::to<std::unordered_set<coordinate>>;
+}
+
+} // namespace aoc::day_8

day_8/lib/coordinate.hpp

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <cstddef>
+#include <memory>
+
+namespace aoc::day_8 {
+
+struct coordinate {
+    int64_t y;
+    int64_t x;
+
+    auto operator!=(coordinate const & other) const -> bool {
+        return y != other.y || x != other.x;
+    }
+
+    auto operator==(coordinate const & other) const -> bool {
+        return y == other.y && x == other.x;
+    }
+
+    [[nodiscard]] auto operator-(coordinate const & other) const -> coordinate {
+        return {y - other.y, x - other.x};
+    }
+
+    [[nodiscard]] auto operator+(coordinate const & other) const -> coordinate {
+        return {y + other.y, x + other.x};
+    }
+
+    auto operator*(int64_t scalar) const -> coordinate {
+        return {y * scalar, x * scalar};
+    }
+
+    auto operator+=(coordinate const & other) -> coordinate & {
+        y += other.y;
+        x += other.x;
+        return *this;
+    }
+
+    [[nodiscard]] auto inBounds(int64_t max_x, int64_t max_y) const -> bool {
+        return y >= 0 && y < max_y && x >= 0 && x < max_x;
+    }
+};
+
+} // namespace aoc::day_8
+namespace std {
+
+/// @brief Hash specialization for VisitedPosition to enable use in unordered containers
+template <> struct hash<aoc::day_8::coordinate> {
+    /// @brief Combines the hashes of row, column and direction into a single hash value
+    /// @param position The position to hash
+    /// @return A hash value representing the complete state of the position
+    [[nodiscard]] auto operator()(aoc::day_8::coordinate const position) const -> std::size_t {
+        return std::hash<int64_t>{}(position.y) ^ std::hash<int64_t>{}(position.x);
+    }
+};
+} // namespace std

day_8/lib/frequency_map_renderer.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <map>
+#include <numeric>
+#include <ranges>
+#include <string>
+#include <unordered_set>
+#include <vector>
+
+#include "../../shared/src/print_compatibility_layer.hpp"
+
+#include "../lib/coordinate.hpp"
+
+namespace aoc::day_8 {
+auto renderResult(std::vector<std::string_view> lines, std::unordered_set<aoc::day_8::coordinate> antinodes,
+                  int64_t max_x_coordinate, int64_t max_y_coordinate) -> void {
+    std::string output = "";
+    for (auto x : std::views::iota(int64_t{0}, max_y_coordinate)) {
+        for (auto y : std::views::iota(int64_t{0}, max_x_coordinate)) {
+            if (antinodes.contains({x, y})) {
+                output += '#';
+            } else {
+                output += lines[x][y];
+            }
+        }
+        output += '\n';
+    }
+    std::println("Result:\n{}Found {} antinodes", output, antinodes.size());
+}
+} // namespace aoc::day_8

day_8/performance/CMakeLists.txt

@@ -0,0 +1 @@
+aoc_add_benchmark()

day_8/src/CMakeLists.txt

@@ -0,0 +1,2 @@
+aoc_add_executable()
+configure_file(input.txt input.txt COPYONLY)

day_8/src/input.txt

@@ -0,0 +1,50 @@
+...............e.........................i........
+...............................1.......i.0........
+..............................s.0......d..........
+........................i....B.I............d.....
+.............................s....................
+................J.................................
+.....................L.....0i.......4...d.........
+.N...e...........................s..R.....4.....I.
+........e.........v................1......R....I..
+.............G..............0.....1...............
+..2...N.............B......................4...R..
+..............2...................N..........4s...
+..p...................................1..b..I.....
+..................p...........B........b...R......
+....................................b.............
+........W.......C.....w...........................
+............7....u.............B..................
+...W.................u......................bw....
+.......p.2...........v......................9.....
+.E.....C....u................................9....
+E....Y................u.D........9...........J....
+.......2..........................................
+............................J.................c...
+.............7...K..D..............J..............
+.....C.Wq........t.................T..............
+............Yt......v.............................
+..W......................3...............w........
+..7.....j................T...D.....n......8.....c.
+.........E...............nTD......................
+...r....E..........Y............n.......P........c
+......K........G......L...........................
+......................G.....L....v................
+..............G...t......q.............l.8........
+......................q............l..............
+...6........r.............................w..c....
+..6.........3.......Qk........T...................
+......Y...............j.................n.........
+..K.....S.....r......j.....U......9.l......8......
+........................U......................P..
+.....................q............................
+.......K......5..N.....j.7.Q......................
+...................p..k...U..........L.Q..........
+.r......3...S.......k........y....8U....Q.......P.
+.......S....g..3..................................
+.....S..........gk................................
+................5...................yP............
+.......................g......yV..l...............
+.........6.5...............V......................
+..................6..5..V.........................
+.............g.......................y..........V.

day_8/src/main.cpp

@@ -0,0 +1,58 @@
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <execution>
+#include <map>
+#include <ranges>
+#include <string>
+#include <unordered_set>
+#include <vector>
+
+#include "../../shared/src/exit_code.hpp"
+#include "../../shared/src/file_operations.hpp"
+#include "../../shared/src/grid_processor.hpp"
+#include "../../shared/src/print_compatibility_layer.hpp"
+
+#include "../lib/antinodes.hpp"
+#include "../lib/coordinate.hpp"
+#include "../lib/frequency_map_renderer.hpp"
+
+auto main(int argc, char const ** argv) -> int {
+    std::expected<std::string, std::error_code> input = aoc::file_operations::read("input.txt");
+    if (!input) [[unlikely]] {
+        std::println(stderr, "Could not open file: {}", input.error().message());
+        return aoc::EXIT_CODE_IO_ERROR;
+    }
+
+    std::vector<std::string_view> lines = aoc::grid_processor::processLines(*input);
+    if (!aoc::grid_processor::validateGrid(lines)) {
+        std::println(stderr, "Lines have different lengths");
+        return aoc::EXIT_CODE_DATA_ERROR;
+    }
+
+    int64_t max_y_coordinate = lines.size();
+    int64_t max_x_coordinate = lines[0].size();
+
+    std::multimap<char, aoc::day_8::coordinate> antenas;
+    for (auto x : std::views::iota(int64_t{0}, max_y_coordinate)) {
+        for (auto y : std::views::iota(int64_t{0}, max_x_coordinate)) {
+            if (std::isalnum(lines[x][y])) {
+                antenas.insert({lines[x][y], {x, y}});
+            }
+        }
+    }
+
+    // Part 1
+    std::unordered_set<aoc::day_8::coordinate> antinodes =
+        aoc::day_8::determineAntinodes(max_x_coordinate, max_y_coordinate, antenas);
+
+    aoc::day_8::renderResult(lines, antinodes, max_x_coordinate, max_y_coordinate);
+
+    // Part 2
+    std::unordered_set<aoc::day_8::coordinate> antinodes2 =
+        aoc::day_8::determineAntinodes2(max_x_coordinate, max_y_coordinate, antenas);
+
+    aoc::day_8::renderResult(lines, antinodes2, max_x_coordinate, max_y_coordinate);
+
+    return 0;
+}

day_8/test/CMakeLists.txt

@@ -0,0 +1 @@
+aoc_add_test()

shared/src/column_splitter.hpp

@@ -1,5 +1,5 @@
 /**
- * @file multiset_column_lexer.hpp
+ * @file column_splitter.hpp
  * @brief Implementation of a lexer that parses the input data into columnar container structures
  * @details Provides interfaces for parsing input data containing columns of numbers.
  * Includes utilities for parsing individual lines and complete input files,

shared/src/line_splitter.hpp

@@ -1,6 +1,6 @@
 /**
- * @file line_lexer.hpp
- * @brief Implementation of a line-based lexer for tokenizing input text
+ * @file line_splitter.hpp
+ * @brief Implementation of a line-based splitter for tokenizing input text
  * @details Provides interfaces for parsing input data line by line into configurable containers.
  * Supports both sequential and parallel processing modes with error handling through std::expected.
  * Container types can be specified through template parameters, with std::vector as the default.