Compilare: main.cpp: In function 'int main()': main.cpp:45:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=dg[x];i<a[x].size();i++) ~^~~~~~~~~~~~ main.cpp:24:36: 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); ^ main.cpp:25:38: 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); ^