Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:11:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ user.cpp:14:18: 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:33:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.in","r",stdin); ^ user.cpp:34:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.out","w",stdout); ^ user.cpp:36:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:39:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^