Compilare: user.cpp: In function ‘void euler(int, int)’: user.cpp:18:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<v[y].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:33:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in","r",stdin); ^ user.cpp:34:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out","w",stdout); ^