Compilare: user.cpp: In function ‘int calc(int)’: user.cpp:20:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nb[s[i]]){ ^ user.cpp:24:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] else if(sus[s[i]]){ ^ user.cpp:29:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] sus[s[i]] = 1; ^ user.cpp: In function ‘int main()’: user.cpp:51:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[s[n]]++; ^ user.cpp:46:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, MAXN + 2, in); ^