80 lines
1.7 KiB
C++
80 lines
1.7 KiB
C++
#include <algorithm>
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#include <cstdint>
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#include <functional>
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#include <iostream>
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#include <numeric>
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#include <sstream>
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#include <vector>
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#include <doctest.h>
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#include <aocpp/Grid.hpp>
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#include <aocpp/Coord.hpp>
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#include <aocpp/Startup.hpp>
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using namespace aocpp;
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namespace {
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using Dir = Coord(*)(Coord);
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Dir directions[4] {Up, Down, Left, Right};
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auto Part1(Grid const& grid) -> std::int64_t
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{
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std::int64_t result {0};
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grid.each([&](Coord const c, char const v) {
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result += std::any_of(
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std::begin(directions), std::end(directions),
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[&](Dir const dir) {
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for (auto x = dir(c); grid.contains(x); x = dir(x)) {
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if (grid[x] >= v) { return false; }
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}
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return true;
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});
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});
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return result;
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}
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auto Part2(Grid const& grid) -> std::int64_t
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{
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std::int64_t result {0};
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grid.each([&](Coord const c, char const v) {
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auto score = std::transform_reduce(
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std::begin(directions), std::end(directions),
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std::int64_t{1}, std::multiplies(), // product
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[&](Dir const dir) {
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std::int64_t count {0};
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for (auto x = dir(c); grid.contains(x); x = dir(x)) {
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count++;
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if (grid[x] >= v) break;
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}
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return count;
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});
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if (result < score) result = score;
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});
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return result;
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}
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} // namespace
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TEST_SUITE("2022-08 examples") {
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TEST_CASE("example") {
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std::istringstream in {
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"30373\n"
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"25512\n"
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"65332\n"
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"33549\n"
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"35390\n"};
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auto grid = aocpp::Grid::Parse(in);
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CHECK(Part1(grid) == 21);
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CHECK(Part2(grid) == 8);
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}
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}
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auto Main(std::istream & in) -> void
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{
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auto const grid = Grid::Parse(in);
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std::cout << "Part 1: " << Part1(grid) << std::endl;
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std::cout << "Part 2: " << Part2(grid) << std::endl;
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}
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