foo.cc:8:1: error: expected initializer before 'int'
    8 | int dist(const stu &a,const stu &b)
      | ^~~
foo.cc: In function 'int main()':
foo.cc:16:15: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and '<unresolved overloaded function type>')
   16 |         cin>>n>>endl;
      |         ~~~~~~^~~~~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:120:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  120 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:120:36: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'}
  120 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:124:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]'
  124 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:124:32: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
  124 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:131:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  131 |       operator>>(ios_base& (*__pf)(ios_base&))
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:131:30: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::ios_base& (*)(std::ios_base&)'
  131 |       operator>>(ios_base& (*__pf)(ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:168:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  168 |       operator>>(bool& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:168:24: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'bool&'
  168 |       operator>>(bool& __n)
      |                  ~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:172:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]'
  172 |       operator>>(short& __n);
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:172:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short int&'
  172 |       operator>>(short& __n);
      |                  ~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:175:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  175 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:175:34: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short unsigned int&'
  175 |       operator>>(unsigned short& __n)
      |                  ~~~~~~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:179:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]'
  179 |       operator>>(int& __n);
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:179:23: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'int&'
  179 |       operator>>(int& __n);
      |                  ~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:182:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  182 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:182:32: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'unsigned int&'
  182 |       operator>>(unsigned int& __n)
      |                  ~~~~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:186:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  186 |       operator>>(long& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:186:24: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long int&'
  186 |       operator>>(long& __n)
      |                  ~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:190:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  190 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:190:33: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long unsigned int&'
  190 |       operator>>(unsigned long& __n)
      |                  ~~~~~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:195:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  195 |       operator>>(long long& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:195:29: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long int&'
  195 |       operator>>(long long& __n)
      |                  ~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  199 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:199:38: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long unsigned int&'
  199 |       operator>>(unsigned long long& __n)
      |                  ~~~~~~~~~~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:214:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  214 |       operator>>(float& __f)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:214:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'float&'
  214 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:218:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  218 |       operator>>(double& __f)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:218:26: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'double&'
  218 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:222:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  222 |       operator>>(long double& __f)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:222:31: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long double&'
  222 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:235:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]'
  235 |       operator>>(void*& __p)
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:235:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'void*&'
  235 |       operator>>(void*& __p)
      |                  ~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:259:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]'
  259 |       operator>>(__streambuf_type* __sb);
      |       ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:259:36: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_istream<char>::__streambuf_type*' {aka 'std::basic_streambuf<char>*'}
  259 |       operator>>(__streambuf_type* __sb);
      |                  ~~~~~~~~~~~~~~~~~~^~~~
In file included from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/string:56,
                 from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/locale_classes.h:40,
                 from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/ios_base.h:41,
                 from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/ios:42,
                 from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/ostream:38,
                 from iostream:39:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/basic_string.tcc:1485:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 1485 |     operator>>(basic_istream<_CharT, _Traits>& __in,
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/basic_string.tcc:1485:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   couldn't deduce template parameter '_Alloc'
   16 |         cin>>n>>endl;
      |                 ^~~~
In file included from /nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:995,
                 from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/istream.tcc:958:5: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&) [with _CharT = char; _Traits = std::char_traits<char>]'
  958 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/bits/istream.tcc:958:62: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'char&'
  958 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
      |                                                      ~~~~~~~~^~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:756:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)'
  756 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:756:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   cannot convert 'std::endl' (type '<unresolved overloaded function type>') to type 'unsigned char&'
   16 |         cin>>n>>endl;
      |                 ^~~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:761:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)'
  761 |     operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:761:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   cannot convert 'std::endl' (type '<unresolved overloaded function type>') to type 'signed char&'
   16 |         cin>>n>>endl;
      |                 ^~~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:803:5: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT*) [with _CharT = char; _Traits = std::char_traits<char>]'
  803 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:803:62: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'char*'
  803 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
      |                                                      ~~~~~~~~^~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:825:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)'
  825 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:825:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   cannot convert 'std::endl' (type '<unresolved overloaded function type>') to type 'unsigned char*'
   16 |         cin>>n>>endl;
      |                 ^~~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:831:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)'
  831 |     operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:831:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   cannot convert 'std::endl' (type '<unresolved overloaded function type>') to type 'signed char*'
   16 |         cin>>n>>endl;
      |                 ^~~~
In file included from iostream:40:
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:985:5: note: candidate: 'template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&)'
  985 |     operator>>(_Istream&& __is, _Tp&& __x)
      |     ^~~~~~~~
/nix/store/l4dvshb0bw0ipyx17f6rknzk83mdx81y-gcc-11.3.0/include/c++/11.3.0/istream:985:5: note:   template argument deduction/substitution failed:
foo.cc:16:17: note:   couldn't deduce template parameter '_Tp'
   16 |         cin>>n>>endl;
      |                 ^~~~
foo.cc:19:22: error: 's' was not declared in this scope
   19 |                 cin>>s[i].x>>s[i].y>>endl;
      |                      ^
foo.cc:23:27: error: 's' was not declared in this scope
   23 |                 sum+=dist(s[i-1],s[i]);
      |                           ^
foo.cc:23:22: error: 'dist' was not declared in this scope
   23 |                 sum+=dist(s[i-1],s[i]);
      |                      ^~~~

[Hydro](https://hydro.ac)提供评测服务