Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:21:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[Nod].size(); ++i) ^ user.cpp:27:36: 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:37:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbore4.in", "r", stdin); ^ user.cpp:38:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbore4.out", "w", stdout); ^ user.cpp:39:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:42:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &A, &B); ^