Compilare: user.cpp: In function ‘void df()’: user.cpp:16:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[x].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:24:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("berarii2.in","r",stdin); ^ user.cpp:25:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("berarii2.out","w",stdout); ^ user.cpp:26:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&k);rez=n; ^ user.cpp:27:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=m;i++) scanf("%d %d",&a,&b),v[b].push_back(a); ^ user.cpp:28:71: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=k;i++) scanf("%d",&y),c.push_back(y),viz[y]=true,rez--; ^