View Compilation Error

0_0_2895851_28858.cpp
0_0_2895851_28858.cpp(9) : error C2079: “cin”使用未定义的 class“std::basic_ifstream<_Elem,_Traits>”
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>
        ]
        0_0_2895851_28858.cpp(9) : 参见对正在编译的类模板实例化“std::basic_ifstream<_Elem,_Traits>”的引用
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>
        ]
        0_0_2895851_28858.cpp(9) : 参见对正在编译的类模板实例化“std::basic_ifstream<_Elem,_Traits>”的引用
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>
        ]
0_0_2895851_28858.cpp(9) : error C2440: “初始化” : 无法从“const char [8]”转换为“int”
        该转换要求 reinterpret_cast、C 样式转换或函数类型转换