CPP

c++ Testing implementation details for automated assessment of sorting algorithms

struct S
{
  static std::vector<std::pair<int, int>> * comparisonLog;

  int x;

  S(int t_x) : x(t_x) { }

  bool operator <(const S & t_other) const
  {
      comparisonLog->push_back({x, t_other.x});
      
      return x < t_other.x;
  }
};

std::vector<std::pair<int, int>> * S::comparisonLog;

//test

    std::vector<std::pair<int, int>> referenceComparisons, studentComparisons;

    const std::vector<S> values = { 1, 5, 4, 3, 2 };

    S::comparisonLog = &referenceComparisons;
    {
      auto toSort = values;
      std::sort(toSort.begin(), toSort.end());
    }

    S::comparisonLog = &studentComparisons;
    {
        auto toSort = values;
        studentSort(toSort);
        assert(std::is_sorted(toSort.begin(), toSort.end()));
    }

    assert(referenceComparisons == studentComparisons);