2025 day 05 p2

2025/day08.cpp

@@ -0,0 +1,112 @@
+#include <span>
+#include <algorithm>
+#include <ranges>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
+#include <tuple>
+
+#include "fmt/std.h"
+
+#include "aoc/types.hpp"
+#include "aoc/utils.hpp"
+
+using namespace std::string_view_literals;
+using namespace aoc::types;
+
+// starts at 50
+[[maybe_unused]]constexpr auto raw_str = R"(
+162,817,812
+57,618,57
+906,360,560
+592,479,940
+352,342,300
+466,668,158
+542,29,236
+431,825,988
+739,650,466
+52,470,668
+216,146,977
+819,987,18
+117,168,530
+805,96,715
+346,949,466
+970,615,88
+941,993,340
+862,61,35
+984,92,344
+425,690,689
+)";
+
+static auto entry([[maybe_unused]]std::span<char const*> const& args) -> void {
+    // std::string str{raw_str};
+    auto str = aoc::read_text("./input.txt").value_or("");
+    str = aoc::trim(str);
+
+    auto mat = str | std::views::split("\n"sv) | std::views::transform([](auto line) {
+                    return line | std::views::split(""sv)
+                                | std::views::transform([](auto tok) {
+                                        return std::string{std::begin(tok), std::end(tok)};
+                                    })
+                                | std::ranges::to<std::vector>();
+      }) | std::ranges::to<std::vector>();
+
+    struct beam {
+        usize row;
+        usize col;
+    };
+
+    std::vector<beam> beams{};
+    for (usize i = 0; i < mat.size(); ++i) {
+        for (usize j = 0; j < mat[i].size(); ++j) {
+            if (mat[i][j] == "S") {
+                beams.push_back({i, j});
+                break;
+            }
+
+            auto const size = beams.size();
+            for (usize k = 0; k < size; ++k) {
+                if (beams[k].row == i - 1 && beams[k].col == j) {
+                    if (mat[i][j] == ".") {
+                        mat[i][j] = "|";
+                        beams[k] = {i, j};
+                    } else if (mat[i][j] == "^") {
+                        beams[k] = {i, j - 1};
+                        beams.push_back({i, j + 1});
+                        mat[i][j - 1] = "|";
+                        mat[i][j + 1] = "|";
+                    }
+                }
+            }
+        }
+    }
+
+    f64 sum = 0.0;
+    for (usize i = 0; i < mat.size(); ++i) {
+        for (usize j = 0; j < mat[i].size(); ++j) {
+            if (mat[i][j] == "^") {
+                if (mat[i - 1][j] == "|") sum += 1;
+            }
+        }
+    }
+
+    fmt::print("res: {}\n", sum);
+
+    // for (auto const& row : mat) {
+    //     for (auto const& col : row) {
+    //         fmt::print("{}", col);
+    //     }
+    //     fmt::print("\n");
+    // }
+}
+
+auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
+    try {
+        entry({argv, std::next(argv, argc)});
+    } catch (std::exception const& e) {
+        fmt::print(stderr, "{}\n", e.what());
+        return 1;
+    }
+    return 0;
+}