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aoc24: day02a complete

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mnerv
2024-12-02 21:31:24 +01:00
parent 311ccc0e71
commit 242f599c8a
1 changed files with 56 additions and 13 deletions
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69
aoc.cpp
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@@ -8,12 +8,12 @@
#include "fmt/format.h" #include "fmt/format.h"
using levels_t = std::vector<std::uint32_t>; using levels_t = std::vector<std::int32_t>;
using reports_t = std::vector<levels_t>; using reports_t = std::vector<levels_t>;
auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int { auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
constexpr auto filename = "./dat/24/ex/02.txt"; constexpr auto filename = "./dat/24/ex/02.txt";
std::ifstream strm{filename, std::ios::in}; std::ifstream strm{filename, std::ios::in | std::ios::binary};
if (!strm.is_open()) { if (!strm.is_open()) {
fmt::print("Error opening file: {}\n", filename); fmt::print("Error opening file: {}\n", filename);
return 1; return 1;
@@ -21,7 +21,7 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
reports_t reports{}; reports_t reports{};
levels_t levels{}; levels_t tmp{};
std::string str{}; std::string str{};
while (strm) { while (strm) {
auto const c = char(strm.peek()); auto const c = char(strm.peek());
@@ -29,20 +29,63 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
str += char(strm.get()); str += char(strm.get());
continue; continue;
} }
if (c == ' ') { if (c == ' ' && !str.empty()) {
if (!str.empty()) { tmp.emplace_back(std::stoi(str));
levels.emplace_back(std::stoi(str)); str.clear();
str.clear();
}
} }
if (c == '\n') { if (c == '\n' && !str.empty()) {
if (!str.empty()) { tmp.emplace_back(std::stoi(str));
reports.emplace_back(std::move(levels)); reports.emplace_back(std::move(tmp));
str.clear(); str.clear();
}
} }
strm.get(); strm.get();
} }
// auto diff = reports | std::views::transform([](auto const& levels) {
// return levels | std::views::slide(2) | std::views::transform([](auto pair) {
// return pair[1] - pair[0];
// });
// });
auto diff = reports | std::views::transform([](auto const& levels) {
return levels | std::views::adjacent_transform<2>([](auto const& a, auto const& b) {
return b - a;
});
});
// condition: all increasing or all decreasing.
auto incdec = diff | std::views::filter([](auto const& levels) {
auto const n = std::ranges::all_of(levels, [](auto v) { return v < 0; });
auto const p = std::ranges::all_of(levels, [](auto v) { return v > 0; });
return n || p;
});
// condition: Any two adjacent levels differ by at least one and at most three.
auto adjdiff = incdec | std::views::filter([](auto const& levels){
return std::ranges::all_of(levels, [](auto v) {
return std::abs(v) <= 3;
});
});
auto const safe_reports = std::ranges::distance(adjdiff);
fmt::print("Part A: {}\n", safe_reports);
for (auto levels : reports) {
for (auto level : levels) {
fmt::print("{} ", level);
}
fmt::print("\n");
}
fmt::print("--------------------------------------------------------------------------------\n");
for (auto levels : diff) {
for (auto level : levels) {
fmt::print("{} ", level);
}
fmt::print("\n");
}
return 0; return 0;
} }