Compilare: main.cpp: In function 'void combinatorics::permutationsGenerator(unsigned int, unsigned int, std::vector<int>&, std::vector<bool>&, std::ostream&)': main.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<=n;++i) ~^~~ main.cpp: In function 'void combinatorics::arrangementsGenerator(unsigned int, unsigned int, unsigned int, std::vector<int>&, std::vector<bool>&, std::ostream&)': main.cpp:45:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<=n;++i) ~^~~ main.cpp: In function 'int main()': main.cpp:68:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin); ^ main.cpp:69:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.out","w",stdout); ^