Compilare: user.cpp: In function ‘int factor()’: user.cpp:59:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] r = v[s[i]]; ^ user.cpp: In function ‘int main()’: user.cpp:114:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(v[lt] == 0){ ^ user.cpp:115:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[lt] = 1; ^ user.cpp:118:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[lt] = 0; ^