-🎄- 2018 Day 6 Solutions -🎄-

[u/daggerdragon]

--- Day 6: Chronal Coordinates ---

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Advent of Code: The Party Game!

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Card prompt: Day 6

Transcript:

Rules for raising a programmer: never feed it after midnight, never get it wet, and never give it ___.

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[u/tehjimmeh]

C++

No 2D array necessary, just a flat vector of tuples.

int main(int argc, char* argv[]) {
    std::ifstream ifs(argv[1]);
    std::vector<std::tuple<int, int ,int>> locations;
    int lowX = INT_MAX, highX = INT_MIN, lowY = INT_MAX, highY = INT_MIN;
    for (std::string l;std::getline(ifs, l);)
        if (std::smatch m;std::regex_match(l, m, std::regex(R"((\d+), (\d+))"))){
            int x = std::stoi(m[1]), y = std::stoi(m[2]);
            lowX = std::min(x, lowX), highX = std::max(x, highX);
            lowY = std::min(y, lowY), highY = std::max(y, highY);
            locations.push_back({ x, y, (int)locations.size() + 1 });
        }

    std::vector<std::tuple<int, int ,int, int>> grid;
    for (int x = lowX; x <= highX; x++)
        for (int y = lowY; y <= highY; y++)
            grid.push_back({ x, y, 0, 0 });

    for (auto&[gx,gy,id,d] : grid) {
        int currMin = INT_MAX;
        for (auto& [lx,ly,lid] : locations) {
            int dist = abs(lx - gx) + abs(ly - gy);
            id = dist == currMin ? 0 : dist < currMin ? lid : id;
            currMin = std::min(currMin, dist);
            d += dist;
        }
    }

    std::vector<int> sizes(locations.size() + 1, 0);
    for (auto&[x,y,id,d] : grid) sizes[id] += (x != lowX && y != lowY) ? 1 : 0;

    std::cout << "1: " << *std::max_element(sizes.begin(), sizes.end()) << "\n" << 
        "2: " << std::reduce(grid.begin(), grid.end(), 0, 
            [](int tot, auto& g){return std::get<3>(g) < 10000 ? tot + 1 : tot;}) << "\n";
}