Eroare de compilare: user.cpp: In function ‘std::vector<int> first_occurence(const string&, const string&)’: user.cpp:20:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (it2 == key.size()) ^ user.cpp: In function ‘int main()’: user.cpp:37:18: error: variable ‘std::ifstream in’ has initializer but incomplete type std::ifstream in("strmatch.in"); ^ user.cpp:38:19: error: variable ‘std::ofstream out’ has initializer but incomplete type std::ofstream out("strmatch.out"); ^