Compilare: user.cpp: In function ‘int main()’: user.cpp:17:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("subsir2.in", "r", stdin); ^ user.cpp:18:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("subsir2.out", "w", stdout); ^ user.cpp:21:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:24:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &v[i]); ^ user.cpp:56:5: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] for (; pos != -1; pos = to[pos]) ^