Compilare: user.cpp: In function ‘void hash_insert(const std::pair<int, int>&)’: user.cpp:50:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(hash_find(x.first) == L[key].size() ) ^ user.cpp: In function ‘int hash_find(const int&)’: user.cpp:58:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[key].size(); i ++) ^ user.cpp: In function ‘int main()’: user.cpp:135:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("autobuze.in", "r", stdin); ^