/in/foo.cc:4:4: error: stray '\345' in program
 100分算法
    ^
/in/foo.cc:4:5: error: stray '\210' in program
 100分算法
     ^
/in/foo.cc:4:6: error: stray '\206' in program
 100分算法
      ^
/in/foo.cc:4:7: error: stray '\347' in program
 100分算法
       ^
/in/foo.cc:4:8: error: stray '\256' in program
 100分算法
        ^
/in/foo.cc:4:9: error: stray '\227' in program
 100分算法
         ^
/in/foo.cc:4:10: error: stray '\346' in program
 100分算法
          ^
/in/foo.cc:4:11: error: stray '\263' in program
 100分算法
           ^
/in/foo.cc:4:12: error: stray '\225' in program
 100分算法
            ^
/in/foo.cc:5:1: error: stray '\347' in program
 答案显然是a=n-1且b=n
 ^
/in/foo.cc:5:2: error: stray '\255' in program
 答案显然是a=n-1且b=n
  ^
/in/foo.cc:5:3: error: stray '\224' in program
 答案显然是a=n-1且b=n
   ^
/in/foo.cc:5:4: error: stray '\346' in program
 答案显然是a=n-1且b=n
    ^
/in/foo.cc:5:5: error: stray '\241' in program
 答案显然是a=n-1且b=n
     ^
/in/foo.cc:5:6: error: stray '\210' in program
 答案显然是a=n-1且b=n
      ^
/in/foo.cc:5:7: error: stray '\346' in program
 答案显然是a=n-1且b=n
       ^
/in/foo.cc:5:8: error: stray '\230' in program
 答案显然是a=n-1且b=n
        ^
/in/foo.cc:5:9: error: stray '\276' in program
 答案显然是a=n-1且b=n
         ^
/in/foo.cc:5:10: error: stray '\347' in program
 答案显然是a=n-1且b=n
          ^
/in/foo.cc:5:11: error: stray '\204' in program
 答案显然是a=n-1且b=n
           ^
/in/foo.cc:5:12: error: stray '\266' in program
 答案显然是a=n-1且b=n
            ^
/in/foo.cc:5:13: error: stray '\346' in program
 答案显然是a=n-1且b=n
             ^
/in/foo.cc:5:14: error: stray '\230' in program
 答案显然是a=n-1且b=n
              ^
/in/foo.cc:5:15: error: stray '\257' in program
 答案显然是a=n-1且b=n
               ^
/in/foo.cc:5:21: error: stray '\344' in program
 答案显然是a=n-1且b=n
                     ^
/in/foo.cc:5:22: error: stray '\270' in program
 答案显然是a=n-1且b=n
                      ^
/in/foo.cc:5:23: error: stray '\224' in program
 答案显然是a=n-1且b=n
                       ^
/in/foo.cc:3:1: error: expected unqualified-id before '/' token
 /
 ^
In file included from /usr/include/c++/6/iosfwd:40:0,
                 from /usr/include/c++/6/ios:38,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/include/c++/6/bits/postypes.h:98:11: error: 'ptrdiff_t' does not name a type
   typedef ptrdiff_t streamsize; // Signed integral type
           ^~~~~~~~~
In file included from /usr/include/c++/6/exception:172:0,
                 from /usr/include/c++/6/ios:39,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/include/c++/6/bits/exception_ptr.h:99:30: error: field 'nullptr_t' has incomplete type 'std::__exception_ptr::exception_ptr'
       exception_ptr(nullptr_t) noexcept
                              ^
/usr/include/c++/6/bits/exception_ptr.h:79:11: note: definition of 'class std::__exception_ptr::exception_ptr' is not complete until the closing brace
     class exception_ptr
           ^~~~~~~~~~~~~
/usr/include/c++/6/bits/exception_ptr.h:99:30: error: expected ';' at end of member declaration
       exception_ptr(nullptr_t) noexcept
                              ^
/usr/include/c++/6/bits/exception_ptr.h:99:32: error: expected unqualified-id before 'noexcept'
       exception_ptr(nullptr_t) noexcept
                                ^~~~~~~~
In file included from /usr/include/c++/6/bits/move.h:57:0,
                 from /usr/include/c++/6/bits/nested_exception.h:40,
                 from /usr/include/c++/6/exception:173,
                 from /usr/include/c++/6/ios:39,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/include/c++/6/type_traits:359:31: error: 'std::size_t' has not been declared
   template<typename _Tp, std::size_t _Size>
                               ^~~~~~
/usr/include/c++/6/type_traits:360:25: error: '_Size' was not declared in this scope
     struct is_array<_Tp[_Size]>
                         ^~~~~
/usr/include/c++/6/type_traits:360:31: error: template argument 1 is invalid
     struct is_array<_Tp[_Size]>
                               ^
/usr/include/c++/6/type_traits:558:37: error: 'nullptr_t' is not a member of 'std'
     struct __is_null_pointer_helper<std::nullptr_t>
                                     ^~~
/usr/include/c++/6/type_traits:558:37: error: 'nullptr_t' is not a member of 'std'
/usr/include/c++/6/type_traits:558:51: error: template argument 1 is invalid
     struct __is_null_pointer_helper<std::nullptr_t>
                                                   ^
/usr/include/c++/6/type_traits:1478:32: error: 'size_t' is not a member of 'std'
     : public integral_constant<std::size_t, __alignof__(_Tp)> { };
                                ^~~
/usr/include/c++/6/type_traits:1478:32: note: suggested alternative:
In file included from /usr/include/wchar.h:51:0,
                 from /usr/include/c++/6/cwchar:44,
                 from /usr/include/c++/6/bits/postypes.h:40,
                 from /usr/include/c++/6/iosfwd:40,
                 from /usr/include/c++/6/ios:38,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/lib/gcc/x86_64-linux-gnu/6/include/stddef.h:216:23: note:   'size_t'
 typedef __SIZE_TYPE__ size_t;
                       ^~~~~~
In file included from /usr/include/c++/6/bits/move.h:57:0,
                 from /usr/include/c++/6/bits/nested_exception.h:40,
                 from /usr/include/c++/6/exception:173,
                 from /usr/include/c++/6/ios:39,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/include/c++/6/type_traits:1478:32: error: 'size_t' is not a member of 'std'
     : public integral_constant<std::size_t, __alignof__(_Tp)> { };
                                ^~~
/usr/include/c++/6/type_traits:1478:32: note: suggested alternative:
In file included from /usr/include/wchar.h:51:0,
                 from /usr/include/c++/6/cwchar:44,
                 from /usr/include/c++/6/bits/postypes.h:40,
                 from /usr/include/c++/6/iosfwd:40,
                 from /usr/include/c++/6/ios:38,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/lib/gcc/x86_64-linux-gnu/6/include/stddef.h:216:23: note:   'size_t'
 typedef __SIZE_TYPE__ size_t;
                       ^~~~~~
In file included from /usr/include/c++/6/bits/move.h:57:0,
                 from /usr/include/c++/6/bits/nested_exception.h:40,
                 from /usr/include/c++/6/exception:173,
                 from /usr/include/c++/6/ios:39,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:7:
/usr/include/c++/6/type_traits:1478:61: error: template argument 1 is invalid
     : public integral_constant<std::size_t, __alignof__(_Tp)> { };
                                                             ^
/usr/include/c++/6/type_traits:1478:61: note: invalid template non-type parameter
/usr/include/c++/6/type_traits:1483:32: error: 'size_t' is not a member of 'std'
     : public integral_constant<std::size_t, 0> { };
                                ^~~
/usr/include/c++/6/type_traits:1483:32: note: suggested alternative:
In file included from /usr/include/wchar.h:51:0,
                 from /usr/include/c++/6/cwchar:44,
                 from /usr/include/c++/6/bits/postypes.h:40,
                 from /usr/include/c++/6/iosfwd:40,
                 from /usr/include/c++/6/ios:38,
                 from /usr/include/c++/6/ostream:38,