aocpp/day11.cpp

#include <iostream>
#include <utility>
#include <tuple>
#include <map>

#include <intcode/intcode.hpp>
using namespace intcode;

namespace {

using Coord = std::pair<ValueType, ValueType>;

auto Compute(Machine machine, ValueType start)
  -> std::map<Coord, ValueType> {
  
  Coord here {0,0};
  std::map<Coord, ValueType> paint {{here,start}};
  ValueType dx {0};
  ValueType dy {-1};

  for (;;) {
    auto effect = Step(machine);

    if (std::holds_alternative<Halt>(effect)) {
      return paint;
    }

    std::get<Input>(effect).pos = paint[here];
    paint[here] = std::get<Output>(Step(machine)).val;
    auto dir = std::get<Output>(Step(machine)).val;

    std::swap(dx, dy);
    if (dir) {  
      dx = -dx;
    } else {
      dy = -dy;
    }
    here.first += dx;
    here.second += dy;
  }
}

auto Draw(std::ostream & out, std::map<Coord, ValueType> image) {
  ValueType minX = 0, maxX = 0, minY = 0, maxY = 0;
  for (auto&& [k, _] : image) {
    auto [x,y] = k;
    minX = std::min(minX, x);
    maxX = std::max(maxX, x);
    minY = std::min(minY, y);
    maxY = std::max(maxY, y);
  }
  for (ValueType y = minY; y <= maxY; y++) {
    for (ValueType x = minX; x <= maxX; x++) {
      out << (image[{x,y}] ? "▓" : "░");
    }
    out << "\n";
  }
}

} // namespace

auto main() -> int {
  auto machine = Machine{ParseStream(std::cin)};
  std::cout << "Part 1: " << Compute(machine, 0).size() << "\nPart 2\n";
  Draw(std::cout, Compute(std::move(machine), 1));
}