Compilare: user.cpp: In function ‘bool element()’: user.cpp:20:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] else {k=v[s[p]];p+=2;} ^ user.cpp: In function ‘int main()’: user.cpp:47:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[c]=!v[c]; ^ user.cpp:47:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[c]=!v[c]; ^