68 lines
1.8 KiB
C++
68 lines
1.8 KiB
C++
//
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// Created by Matthew Gretton-Dann on 05/12/2021.
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//
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#include <iostream>
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#include <map>
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#include <numeric>
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#include <regex>
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#include <string>
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using Point = std::pair<unsigned, unsigned>;
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auto get_points(std::string const& s) -> std::pair<Point, Point>
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{
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static std::regex re{R"((\d+),(\d+) -> (\d+),(\d+))"};
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std::smatch m;
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if (!std::regex_search(s, m, re)) {
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std::cerr << "Unable to interpret: " << s << "\n";
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std::exit(1);
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}
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return {{std::stoul(m.str(1)), std::stoul(m.str(2))},
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{std::stoul(m.str(3)), std::stoul(m.str(4))}};
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}
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auto main() -> int
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{
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std::string line;
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std::map<Point, unsigned> vents;
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while (std::getline(std::cin, line)) {
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auto [pt1, pt2] = get_points(line);
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std::cout << "{" << pt1.first << ", " << pt1.second << "} -> {" << pt2.first << ", "
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<< pt2.second << "}: ";
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if (pt1.first == pt2.first) {
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unsigned y1{std::min(pt1.second, pt2.second)};
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unsigned y2{std::max(pt1.second, pt2.second)};
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std::cout << "vertical:\n";
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while (y1 <= y2) {
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auto [it, success] = vents.insert({{pt1.first, y1}, 1});
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if (!success) {
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++(it->second);
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}
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++y1;
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}
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}
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else if (pt1.second == pt2.second) {
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unsigned x1{std::min(pt1.first, pt2.first)};
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unsigned x2{std::max(pt1.first, pt2.first)};
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std::cout << "horizontal:\n";
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while (x1 <= x2) {
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auto [it, success] = vents.insert({{x1, pt1.second}, 1});
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if (!success) {
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++(it->second);
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}
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++x1;
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}
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}
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else {
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std::cout << "sloped\n";
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}
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}
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auto danger_count{
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std::accumulate(vents.begin(), vents.end(), unsigned{0},
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[](auto a, auto const& it) { return a + (it.second >= 2 ? 1 : 0); })};
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std::cout << "Danger spots: " << danger_count << '\n';
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return 0;
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} |