Compilare: user.cpp: In function ‘int main()’: user.cpp:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.length(); i++) ~~^~~~~~~~~~~~ user.cpp:18:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(++v[s[i]] > 1) ^ user.cpp:7:39: 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:8:41: 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); ^