/in/foo.cc: In function 'int main()':
/in/foo.cc:10:9: error: incompatible types in assignment of 'std::__cxx11::string {aka std::__cxx11::basic_string<char>}' to 'char [100]'
   a[i++]=s;
         ^
/in/foo.cc:13:7: error: no match for 'operator>>' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'char [100]')
   cout>>a[j]>>endl;
       ^
In file included from /usr/include/c++/5/string:53:0,
                 from /usr/include/c++/5/bits/locale_classes.h:40,
                 from /usr/include/c++/5/bits/ios_base.h:41,
                 from /usr/include/c++/5/ios:42,
                 from /usr/include/c++/5/ostream:38,
                 from /usr/include/c++/5/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/5/bits/basic_string.tcc:1441:5: 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>&)
     operator>>(basic_istream<_CharT, _Traits>& __in,
     ^
/usr/include/c++/5/bits/basic_string.tcc:1441:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<_CharT, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/istream:934:0,
                 from /usr/include/c++/5/iostream:40,
                 from /in/foo.cc:1:
/usr/include/c++/5/bits/istream.tcc:955:5: note: candidate: template<class _CharT2, class _Traits2> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT2*)
     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
     ^
/usr/include/c++/5/bits/istream.tcc:955:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<_CharT, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/istream:934:0,
                 from /usr/include/c++/5/iostream:40,
                 from /in/foo.cc:1:
/usr/include/c++/5/bits/istream.tcc:923:5: note: candidate: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)
     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
     ^
/usr/include/c++/5/bits/istream.tcc:923:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<_CharT, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/iostream:40:0,
                 from /in/foo.cc:1:
/usr/include/c++/5/istream:756:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)
     operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
     ^
/usr/include/c++/5/istream:756:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<char, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/iostream:40:0,
                 from /in/foo.cc:1:
/usr/include/c++/5/istream:761:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)
     operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
     ^
/usr/include/c++/5/istream:761:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<char, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/iostream:40:0,
                 from /in/foo.cc:1:
/usr/include/c++/5/istream:803:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)
     operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
     ^
/usr/include/c++/5/istream:803:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<char, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/iostream:40:0,
                 from /in/foo.cc:1:
/usr/include/c++/5/istream:808:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)
     operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
     ^
/usr/include/c++/5/istream:808:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<char, _Traits>'
   cout>>a[j]>>endl;
            ^
In file included from /usr/include/c++/5/iostream:40:0,
                 from /in/foo.cc:1:
/usr/include/c++/5/istream:924:5: note: candidate: template<class _CharT, class _Traits, class _Tp> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&)
     operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
     ^
/usr/include/c++/5/istream:924:5: note:   template argument deduction/substitution failed:
/in/foo.cc:13:12: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'std::basic_istream<_CharT, _Traits>'
   cout>>a[j]>>endl;
            ^