#include <sstream>
#include <exception>
#include <iostream>
#include <string>
#include <map>
#include <set>

using namespace std;


template<class T>
ostream &operator<<(ostream &os, const set<T> &s);


template<class K, class V>
ostream &operator<<(ostream &os, const map<K, V> &m);


template<class T, class U>
void AssertEqual(const T &t, const U &u, const string &hint);


inline void Assert(bool b, const string &hint);


template<class T>
ostream &operator<<(ostream &os, const set<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &x : s) {
    if (!first) {
      os << ", ";
    }
    first = false;
    os << x;
  }
  return os << "}";
}


template<class K, class V>
ostream &operator<<(ostream &os, const map<K, V> &m) {
  os << "{";
  bool first = true;
  for (const auto &kv : m) {
    if (!first) {
      os << ", ";
    }
    first = false;
    os << kv.first << ": " << kv.second;
  }
  return os << "}";
}


template<class T, class U>
void AssertEqual(const T &t, const U &u, const string &hint) {
  if (t!=u) {
    ostringstream os;
    os << "Assertion failed: " << t << " != " << u
       << " hint: " << hint;
    throw runtime_error(os.str());
  }
}


inline void Assert(bool b, const string &hint) {
  AssertEqual(b, true, hint);
}


class TestRunner {
 public:
  template<class TestFunc>
  void RunTest(TestFunc func, const string &test_name);
  ~TestRunner();
 private:
  int fail_count = 0;
};


template<class TestFunc>
void TestRunner::RunTest(TestFunc func, const string &test_name) {
  try {
    func();
    cerr << test_name << " OK" << endl;
  } catch (runtime_error &e) {
    ++fail_count;
    cerr << test_name << " fail: " << e.what() << endl;
  }
}


TestRunner::~TestRunner() {
  if (fail_count > 0) {
    cerr << fail_count << " unit tests failed. Terminate" << endl;
    exit(1);
  }
}