aocpp/intcode/src/Machine.cpp

#include <intcode/Machine.hpp>

namespace intcode {

Machine::Machine() : rom_{}, ram_{}, pc_{0}, base_{0} {}

Machine::Machine(std::vector<ValueType> program)
    : rom_{std::move(program)}, ram_{}, pc_{0}, base_{0} {}

auto Machine::At(std::size_t const i) -> ValueType & {
  return i < rom_.size() ? rom_[i] : ram_[i];
}

auto Machine::At(std::size_t const i) const -> ValueType {
  if (i < rom_.size()) return rom_[i];
  if (auto it = ram_.find(i); it != ram_.end()) { return it->second; }
  return 0;
}

auto Machine::Rel(std::size_t const i) -> ValueType & {
  return At(base_ + i);
}

auto Machine::Rel(std::size_t const i) const -> ValueType {
  return At(base_ + i);
}

auto Machine::Rebase(std::size_t const offset) -> void {
  base_ += offset;
}

auto Machine::Next() -> ValueType & {
  return At(pc_++);
}

auto Machine::Goto(std::size_t const address) -> void {
  pc_ = address;
}

auto Machine::Dump() const -> std::vector<ValueType> {
  if (ram_.empty()) { return rom_; }
  
  std::size_t size = rom_.size();
  for (auto const& [k,v] : ram_) {
    if (k >= size) { size = k+1; }
  }

  std::vector<ValueType> result(size);
  std::copy(rom_.begin(), rom_.end(), result.begin());
  for (auto const& [k,v] : ram_) {
    result[k] = v;
  }

  return result;
}

} // namespace