Compilare: user.cpp: In function ‘int main()’: user.cpp:72:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i<vv.size(); i++) { ~^~~~~~~~~~ user.cpp: In function ‘int root(int)’: user.cpp:43:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:55:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("unique.in", "r", stdin); ^ user.cpp:56:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("unique.out", "w", stdout); ^