typedef NS_ENUM (NSInteger, SubtractState) {
NS_ENUM_Type_Add = 0, //A+B A+B = 18
NS_ENUM_Type_Sub, //A-B A-B = 12
NS_ENUM_Type_Mul, //A*B A*B = 45
NS_ENUM_Type_Div, //A/B A/B = 5
NS_ENUM_Type_Pow, //A的3次方 A*A*A=
NS_ENUM_Type_10Power //A*10的3次方 A * 10*10*10
};
[WSubtractingCounter getCount:@"0" valueB:@"5" states:NS_ENUM_Type_Sub];