Compilare: user.cpp: In function ‘int main()’: user.cpp:39:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] tie (cerc, gr) = grad[c]; ^ user.cpp:29:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cern.in", "r", stdin); ^ user.cpp:30:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cern.out", "w", stdout); ^ user.cpp:34:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%c %d %d", &c, &sens, &timp); ^