Compilare: main.cpp: In function 'bool dfs(int)': main.cpp:13:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<adj[nod].size();i++) ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:23:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("grarb.in","r",stdin); ^ 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("grarb.out","w",stdout); ^