Compilare: user.cpp: In function ‘int main()’: user.cpp:13:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(v[a1]) ^ user.cpp:16:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] a=v[a1]; ^ user.cpp:10:15: warning: ‘a1’ is used uninitialized in this function [-Wuninitialized] char a='1',b,a1; ^ user.cpp:18:42: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] else if((b>='a' and b<='z') or (b>='A' and b<='Z')) y++; ^