Compilare: user.cpp: In function ‘int main()’: user.cpp:53:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i=1;i<=n;++i) ^ user.cpp:45:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("easygraph.in","r",stdin); ^ user.cpp:46:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("easygraph.out","w",stdout); ^