Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<A[nod].size();++i) ^ user.cpp:19:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<A[nod].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:24:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zvon.in","r",stdin); ^ user.cpp:25:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zvon.out","w",stdout); ^ user.cpp:26:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:29:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:33:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^