112 lines
4.0 KiB
C++
112 lines
4.0 KiB
C++
#include <span>
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#include <vector>
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#include <fstream>
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#include <expected>
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#include <system_error>
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#include <ranges>
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#include <string>
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#include <algorithm>
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#include <numeric>
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#include "fmt/format.h"
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#include "aoc/aoc.hpp"
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namespace vfp {
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using namespace aoc::types;
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using order_rule = std::vector<i32>;
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}
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auto entry([[maybe_unused]]std::span<char const*> const& args) -> std::expected<void, aoc::error> {
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using namespace std::string_view_literals;
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// auto txtres = aoc::read_text("./dat/24/ex/05.txt");
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auto txtres = aoc::read_text("./dat/24/re/05.txt");
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if (!txtres) return std::unexpected(txtres.error());
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auto const txt = *txtres;
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auto const not_empty = [](auto const& str) { return !str.empty(); };
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auto lines = txt | std::views::split("\n"sv)
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| std::views::transform([](auto const& str) { return std::string_view(str); });
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auto rules_str = lines | std::views::take_while(not_empty)
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| std::ranges::to<std::vector>();
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auto updates_str = lines | std::views::drop_while(not_empty)
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| std::views::drop(1)
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| std::views::take_while(not_empty)
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| std::ranges::to<std::vector>();
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// fmt::print("rules:\n");
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// std::ranges::for_each(rules_str, [](auto const& str) {
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// fmt::print(" \"{}\"\n", str);
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// });
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// fmt::print("\n");
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//
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// fmt::print("updates:\n");
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// std::ranges::for_each(updates_str, [](auto const& str) {
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// fmt::print(" \"{}\"\n", str);
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// });
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auto order_rules = rules_str | std::views::transform([](auto const& str) {
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return str | std::views::split("|"sv)
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| std::views::transform([](auto const& num_str) {
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return std::stoi(std::string{std::begin(num_str), std::end(num_str)});
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}) | std::ranges::to<std::vector>();
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}) | std::ranges::to<std::vector>();
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auto updates = updates_str | std::views::transform([](auto const& str) {
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return str | std::views::split(","sv)
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| std::views::transform([](auto const& num_str) {
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return std::stoi(std::string{std::begin(num_str), std::end(num_str)});
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}) | std::ranges::to<std::vector>();
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}) | std::ranges::to<std::vector>();
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// std::ranges::for_each(order_rules, [](auto const& rule) {
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// std::ranges::for_each(rule, [](auto const& page) {
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// fmt::print("{} ", page);
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// });
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// fmt::print("\n");
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// });
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//
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// std::ranges::for_each(updates, [](auto const& update) {
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// std::ranges::for_each(update, [](auto const& page) {
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// fmt::print("{}, ", page);
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// });
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// fmt::print("\n");
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// });
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auto valid_updates = updates | std::views::filter([&](auto const& pages) {
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return std::ranges::all_of(order_rules, [&](auto const& rule) {
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auto const a = std::ranges::find(pages, rule[0]);
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auto const b = std::ranges::find(pages, rule[1]);
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return a < b || a == std::end(pages) || b == std::end(pages) || a == b;
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});
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});
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// std::ranges::for_each(valid_updates, [](auto const& update){
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// std::ranges::for_each(update, [](auto const& page) {
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// fmt::print("{}, ", page);
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// });
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// fmt::print("\n");
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// });
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auto mids = valid_updates | std::views::transform([](auto const& updates) {
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return *std::ranges::next(std::begin(updates), updates.size() / 2);
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});
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// std::ranges::for_each(mids, [](auto const& mid) {
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// fmt::print("{}\n", mid);
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// });
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auto const sum = std::accumulate(std::begin(mids), std::end(mids), 0);
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fmt::print("Part A: {}\n", sum);
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return {};
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}
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auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
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auto const res = entry({argv, static_cast<std::size_t>(argc)});
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if (res) return 0;
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fmt::print(stderr, "{}: {}\n", res.error().err.message(), res.error().msg);
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return 1;
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}
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