Compilare: user.cpp: In function ‘int main()’: user.cpp:30:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nd].size();i++) ^ user.cpp:56:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nd].size();i++) ^ user.cpp:10:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in","r",stdin); ^ user.cpp:11:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out","w",stdout); ^ user.cpp:12:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&c,&n,&m); ^ user.cpp:14:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&drg[i]); ^ user.cpp:17:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^