92 lines
2.6 KiB
C++
92 lines
2.6 KiB
C++
#include <fstream>
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#include <vector>
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#include <algorithm>
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#include <ranges>
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#include <numeric>
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#include <cmath>
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#include <utility>
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#include "fmt/format.h"
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using levels_t = std::vector<std::int32_t>;
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using reports_t = std::vector<levels_t>;
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auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
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constexpr auto filename = "./dat/24/ex/02.txt";
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std::ifstream strm{filename, std::ios::in | std::ios::binary};
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if (!strm.is_open()) {
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fmt::print("Error opening file: {}\n", filename);
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return 1;
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}
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reports_t reports{};
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levels_t tmp{};
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std::string str{};
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while (strm) {
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auto const c = char(strm.peek());
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if (std::isdigit(c)) {
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str += char(strm.get());
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continue;
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}
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if (c == ' ' && !str.empty()) {
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tmp.emplace_back(std::stoi(str));
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str.clear();
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}
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if (c == '\n' && !str.empty()) {
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tmp.emplace_back(std::stoi(str));
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reports.emplace_back(std::move(tmp));
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str.clear();
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}
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strm.get();
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}
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// auto diff = reports | std::views::transform([](auto const& levels) {
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// return levels | std::views::slide(2) | std::views::transform([](auto pair) {
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// return pair[1] - pair[0];
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// });
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// });
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auto diff = reports | std::views::transform([](auto const& levels) {
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return levels | std::views::adjacent_transform<2>([](auto const& a, auto const& b) {
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return b - a;
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});
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});
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// condition: all increasing or all decreasing.
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auto incdec = diff | std::views::filter([](auto const& levels) {
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auto const n = std::ranges::all_of(levels, [](auto v) { return v < 0; });
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auto const p = std::ranges::all_of(levels, [](auto v) { return v > 0; });
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return n || p;
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});
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// condition: Any two adjacent levels differ by at least one and at most three.
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auto adjdiff = incdec | std::views::filter([](auto const& levels){
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return std::ranges::all_of(levels, [](auto v) {
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return std::abs(v) <= 3;
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});
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});
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auto const safe_reports = std::ranges::distance(adjdiff);
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fmt::print("Part A: {}\n", safe_reports);
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for (auto levels : reports) {
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for (auto level : levels) {
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fmt::print("{} ", level);
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}
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fmt::print("\n");
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}
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fmt::print("--------------------------------------------------------------------------------\n");
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for (auto levels : diff) {
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for (auto level : levels) {
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fmt::print("{} ", level);
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}
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fmt::print("\n");
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}
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return 0;
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}
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