Compilare: user.cpp: In function ‘int main()’: user.cpp:17:11: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[c[0]] = 1; ^ user.cpp:19:45: warning: array subscript has type ‘char’ [-Wchar-subscripts] while ( ind+1<N && dif + (f[c[ind+1]]==0) <= K ) { ^ user.cpp:21:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!f[c[ind]]) { ^ user.cpp:24:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] ++f[c[ind]]; ^ user.cpp:33:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] --f[c[i]]; ^ user.cpp:34:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (f[c[i]] == 0) --dif; ^