Compilare: user.cpp: In function ‘int main()’: user.cpp:17:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] ++f[s[i]]; ^ user.cpp:18:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (f[s[i]] == 2) ^ user.cpp:8:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dinozaur.in", "r", stdin); ^ user.cpp:9:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dinozaur.out", "w", stdout); ^ user.cpp:12:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] int n; gets(s); ^ /tmp/ccLryNLw.o: In function `main': user.cpp:(.text.startup+0x59): warning: the `gets' function is dangerous and should not be used.