Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:13:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[node].size(); i++) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:23:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<GT[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:32:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:33:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:37:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^