Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:18:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<vec[nod].size(); i++){ ^ user.cpp: In function ‘int main()’: user.cpp:35:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("asmax.in", "r", stdin); ^ user.cpp:36:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("asmax.out", "w", stdout); ^ user.cpp:38:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:41:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%lld", &v[i]); ^ user.cpp:45:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &a, &b); ^