Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:20:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<lista[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:26:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coprime.in","r",stdin); ^ user.cpp:27:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coprime.out","w",stdout); ^ user.cpp:29:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&nr); ^ user.cpp:31:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n1,&n2); ^