Language: C++

#include<bits/stdc++.h>
using namespace std;

int main(){
  vector<string>s();
  vector<string>t();
  cin >> s >> t;

int i=0;
int conunt = 0;
  while(s != t){
    if(s(i) != t(i)){
      s(i) = t(i);
    }
    i++;
    count++;
  }

  cout << count << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:18: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
    5 |   vector<string>s();
      |                  ^~
a.cc:6:18: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
    6 |   vector<string>t();
      |                  ^~
a.cc:7:7: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'std::vector<std::__cxx11::basic_string<char> >()')
    7 |   cin >> s >> t;
      |   ~~~ ^~ ~
      |   |      |
      |   |      std::vector<std::__cxx11::basic_string<char> >()
      |   std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'std::vector<std::__cxx11::basic_string<char> > (*)()'
    7 |   cin >> s >> t;
      |          ^
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'short int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(short int)s' to 'short int&'
/usr/include/c++/14/istream:177:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'short unsigned int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(short unsigned int)s' to 'short unsigned int&'
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(int)s' to 'int&'
/usr/include/c++/14/istream:184:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'unsigned int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(unsigned int)s' to 'unsigned int&'
/usr/include/c++/14/istream:188:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'long int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(long int)s' to 'long int&'
/usr/include/c++/14/istream:192:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'long unsigned int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(long unsigned int)s' to 'long unsigned int&'
/usr/include/c++/14/istream:199:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'long long int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(long long int)s' to 'long long int&'
/usr/include/c++/14/istream:203:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'long long unsigned int' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(long long unsigned int)s' to 'long long unsigned int&'
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'void*' [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
a.cc:7:10: error: cannot bind rvalue '(void*)s' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>; __ios_type = std::basic_ios<char>]' (near match)
  126 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:126:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:10: error: invalid conversion from 'std::vector<std::__cxx11::basic_string<char> > (*)()' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'} [-fpermissive]
    7 |   cin >> s >> t;
      |          ^
      |          |
      |          std::vector<std::__cxx11::basic_string<char> > (*)()
/usr/include/c++/14/istream:133:7: note: candidate: 'std::basic_i