Compilare: user.cpp: In function ‘int factor()’: user.cpp:79:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] r=!v[s[p]]; ^ user.cpp:81:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] r=v[s[p]]; ^ user.cpp: In function ‘int main()’: user.cpp:147:6: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[j] = NULL; ^ user.cpp:153:11: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(v[c] == 0) ^ user.cpp:154:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[c] = 1; ^ user.cpp:156:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[c] = 0; ^ user.cpp: In function ‘int factor()’: user.cpp:86:1: warning: control reaches end of non-void function [-Wreturn-type] } ^