Compilare: main.cpp: In function 'int main()': main.cpp:17:15: warning: array subscript has type 'char' [-Wchar-subscripts] f[v[i]]++; ^ main.cpp:19:19: warning: array subscript has type 'char' [-Wchar-subscripts] if (f[v[i]] == 1) ^ main.cpp:25:19: warning: array subscript has type 'char' [-Wchar-subscripts] f[v[p]]--; ^ main.cpp:26:23: warning: array subscript has type 'char' [-Wchar-subscripts] if (f[v[p]]==0) ^