Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[nod].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmax.in","r",stdin); ^ user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmax.out","w",stdout); ^ user.cpp:33:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:35:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&val[i]); ^ user.cpp:38:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^