Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:13:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:56:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[a].size();i++) ^ user.cpp:19:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.in","r",stdin); ^ user.cpp:20:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.out","w",stdout); ^ user.cpp:22:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:25:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&D,&C,&V); ^ user.cpp:33:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:53:9: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(a!=b) ^