Language: C++

#include<iostream>
using namespace std;
#define debug(x) //printf(x);printf("\n");
int main(){
  int n;

  cin >> n;
  int *v = new int[n+1];
  v[0]=0;
  for(int i=1;i<n+1;i++){
    cin >> v[i] + v[i-1];
    debug("read val");
  }

  sort(v,v+n);
  int cnt = 0;
  int uniq = v[0];
  for(int i=1;i<n+1;i++){
    if( uniq == v[i] ){
      cnt++;
    }
    else{
      uniq=v[i];
    }
  }

  delete(v);
  cout << cnt; 
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:9: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'int')
   11 |     cin >> v[i] + v[i-1];
      |     ~~~ ^~ ~~~~~~~~~~~~~
      |     |           |
      |     |           int
      |     std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 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:11:17: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:7: note:   conversion of argument 1 would be ill-formed:
a.cc:11:17: error: cannot bind non-const lvalue reference of type 'float&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:7: note:   conversion of argument 1 would be ill-formed:
a.cc:11:17: error: cannot bind non-const lvalue reference of type 'double&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/usr/include/c++/14/istream:227:7: 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>; __istream_type = std::basic_istream<char>]' (near match)
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:7: note:   conversion of argument 1 would be ill-formed:
a.cc:11:17: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type 'int'
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
/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:11:17: error: invalid conversion from 'int' to 'void*' [-fpermissive]
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
      |                 |
      |                 int
a.cc:11:17: error: cannot bind rvalue '(void*)((long int)((*(v + ((sizetype)(((long unsigned int)i) * 4)))) + (*(v + (((sizetype)(((long unsigned int)i) * 4)) + 18446744073709551612)))))' 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:11:17: error: invalid conversion from 'int' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
      |                 |
      |                 int
/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:11:17: error: invalid conversion from 'int' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'} [-fpermissive]
   11 |     cin >> v[i] + v[i-1];
      |            ~~~~~^~~~~~~~
      |                 |
      |                 int
/usr/include/c++/14/istream:133:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT