Compilare: main.cpp: In function 'bool factor()': main.cpp:99:24: warning: array subscript has type 'char' [-Wchar-subscripts] val = vval[s[p]]; ^ main.cpp: In function 'int main()': main.cpp:116:27: warning: array subscript has type 'char' [-Wchar-subscripts] if (vval[sirlit[i]] == true) vval[sirlit[i]] = false; ^ main.cpp:116:52: warning: array subscript has type 'char' [-Wchar-subscripts] if (vval[sirlit[i]] == true) vval[sirlit[i]] = false; ^ main.cpp:117:29: warning: array subscript has type 'char' [-Wchar-subscripts] else vval[sirlit[i]] = true; ^