Compilare: main.cpp: In function 'bool factor()': main.cpp:34:26: warning: array subscript has type 'char' [-Wchar-subscripts] 34 | n = val[str[index]]; | ~~~~~~~~~^ main.cpp: In function 'int main()': main.cpp:98:13: warning: array subscript has type 'char' [-Wchar-subscripts] 98 | val[c] = !val[c]; | ^ main.cpp:98:23: warning: array subscript has type 'char' [-Wchar-subscripts] 98 | val[c] = !val[c]; | ^