问怎样用C++比较两个向量？

EN

std::sort(v1.begin(), v1.end());
std::sort(v2.begin(), v2.end());
std::vector<string> v3;
std::set_intersection(v1.begin(), v1.end(), v2.begin(), v2.end(), std::back_inserter(v3));

std::set<string> s1(v1.begin(), v1.end());
std::set<string> s2(v2.begin(), v2.end());
std::vector<string> v3;
std::set_intersection(s1.begin(), s1.end(), s2.begin(), s2.end(), std::back_inserter(v3));

int compare(const vector<string>& left, const vector<string>& right) {
  auto leftIt = left.begin();
  auto rightIt = right.begin();
  auto diff = 0;
  while (leftIt != left.end() && rightIt != right.end()) {
    if (*leftIt != *rightIt) {
      diff++;
    }
    leftIt++;
    rightIt++;
  }

  // Account for different length vector instances
  if (0 == diff && (leftIt != left.end() || rightIt != right.end())) {
    diff = 1;
  }

  return diff;
}