80 lines
1.5 KiB
C++
80 lines
1.5 KiB
C++
#include <cstdint>
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#include <cctype>
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#include <iostream>
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#include <sstream>
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#include <string>
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#include <tuple>
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#include <vector>
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#include <doctest.h>
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#include <aocpp/Startup.hpp>
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#include <aocpp/Grid.hpp>
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#include <aocpp/Coord.hpp>
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using namespace aocpp;
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namespace {
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auto Drive(Grid const& grid) -> std::pair<std::string, int>
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{
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std::string path;
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int steps = 0;
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Coord here {};
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Coord dir {0,1};
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// Find starting column
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for (std::size_t i = 0; i < grid.rows[0].size(); i++) {
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if (grid.rows[0][i] != ' ') {
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here.x = i;
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break;
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}
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}
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for(;;) {
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char c = grid[here];
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if (c == '+') {
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if (grid[here + CW(dir)] != ' ') {
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dir = CW(dir);
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} else if (grid[here + CCW(dir)] != ' ') {
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dir = CCW(dir);
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}
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} else if (c == ' ') {
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break;
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} else if (std::isalpha(c)) {
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path += c;
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}
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steps++;
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here += dir;
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}
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return {path, steps};
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}
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} // namespace
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TEST_SUITE("2017-19 examples") {
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TEST_CASE("example") {
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std::istringstream in {
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" | \n"
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" | +--+ \n"
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" A | C \n"
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" F---|--|-E---+ \n"
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" | | | D \n"
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" +B-+ +--+ \n"
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" \n"
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};
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auto const [p1, p2] = Drive(Grid::Parse(in));
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CHECK(p1 == "ABCDEF");
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CHECK(p2 == 38);
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}
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}
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auto Main(std::istream & in, std::ostream & out) -> void
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{
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auto const [part1, part2] = Drive(Grid::Parse(in));
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out << "Part 1: " << part1 << std::endl;
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out << "Part 2: " << part2 << std::endl;
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}
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