Compilare: user.cpp: In function ‘void df(int)’: user.cpp:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[x].size();j++) ^ user.cpp: In function ‘void df1(int, int)’: user.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[x].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:37:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disconnect.in","r",stdin); ^ user.cpp:38:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disconnect.out","w",stdout); ^ user.cpp:39:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:41:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&a,&b),v[b].push_back(a),v[a].push_back(b); ^ user.cpp:48:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&tip,&x,&y); ^