Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:27:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:42:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp:39:34: 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); ^ user.cpp:40:36: 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); ^ user.cpp:44:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:50:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^