aocpp/2019/02.cpp

#include <iostream>
#include <utility>

#include <doctest.h>

#include <aocpp/Startup.hpp>
#include <intcode/intcode.hpp>


using namespace intcode;

namespace {

auto Compute(Machine machine, ValueType x, ValueType y) {
  machine.At(1) = x;
  machine.At(2) = y;
  Step(machine);
  return machine.At(0);
}

} // namespace

TEST_SUITE("documented examples") {

  auto eval = [](std::vector<ValueType> program, std::vector<ValueType> output) {
    Machine m{program};
    REQUIRE(std::holds_alternative<Halt>(Step(m)));
    REQUIRE(m.Dump() == output);
  };

  TEST_CASE("part 1") {
    eval({1,0,0,0,99}, {2,0,0,0,99});
    eval({2,3,0,3,99}, {2,3,0,6,99});
    eval({2,4,4,5,99,0}, {2,4,4,5,99,9801});
    eval({1,1,1,4,99,5,6,0,99}, {30,1,1,4,2,5,6,0,99});
  }
}

auto Main(std::istream & in) -> void
{
  auto machine = Machine{ParseStream(in)};

  std::cout << "Part 1: " << Compute(machine, 12, 2) << std::endl;

  for (std::int64_t i = 0; i < 100; i++) {
    for (std::int64_t j = 0; j < 100; j++) {
      if (19690720 == Compute(machine, i, j)) {
        std::cout << "Part 2: " << 100 * i + j << std::endl;
      }
    }
  }
}