Language: C++

#include <bits/stdc++.h>
#define int __int128 
const int MODN=1e9+7;
const int MAXN=1e5+10;
using namespace std;
/* Iterative Function to calculate (x^y)%p in O(log y) */
int quick_pow(int x, unsigned int y, int p) 
{ 
    int res = 1;      // Initialize result 
  
    x = x % p;  // Update x if it is more than or  
                // equal to p 
  
    while (y > 0) 
    { 
        // If y is odd, multiply x with result 
        if (y & 1) 
            res = (res*x) % p; 
  
        // y must be even now 
        y = y>>1; // y = y/2 
        x = (x*x) % p;   
    } 
    return res; 
} 
vector<int> fact(MAXN,1);
int C(int n,int r){
	// cerr<<n<<" "<<r<<endl;
	int a=fact[n];int b=fact[n-r]*fact[r];
	return a*quick_pow(b,MODN-2,MODN)%MODN;
}
int32_t main(){
	int n,k;cin>>n>>k;
	vector<int> arrmv(n+1);
	for(int i=1;i<=n;i++)cin>>arrmv[i];
	sort(next(arrmv.begin(),1),arrmv.end());
	
	for(int i=1;i<=n+1;i++){
		fact[i]=i*fact[i-1];
		fact[i]%=MODN;
		// cerr<<fact[i]<<endl;
	}
	int maxsum=0;
	for(int i=k;i<=n;i++){
		// cerr<<arrmv[i]<<" "<<
		maxsum+=arrmv[i]*C(i-1,k-1);
		maxsum%=MODN;
	}
	int minsum=0;
	for(int i=1;i<=n-(k-1);i++){
		minsum+=arrmv[i]*C(n-i,k-1);
		minsum%=MODN;
	}
	assert(maxsum>minsum);
	cout<<(maxsum-minsum)%MODN<<endl;
	return 0;
}

Compiler output:
a.cc: In function 'int32_t main()':
a.cc:33:20: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and '__int128')
   33 |         int n,k;cin>>n>>k;
      |                 ~~~^~~
      |                 |    |
      |                 |    __int128
      |                 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:33:22: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'float&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'double&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type '__int128'
   33 |         int n,k;cin>>n>>k;
      |                      ^
/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:33:22: error: invalid conversion from '__int128' to 'void*' [-fpermissive]
   33 |         int n,k;cin>>n>>k;
      |                      ^
      |                      |
      |                      __int128
a.cc:33:22: error: cannot bind rvalue '(void*)((long int)n)' 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:33:22: error: invalid conversion from '__int128' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   33 |         int n,k;cin>>n>>k;
      |                      ^
      |                      |
      |                      __int128
/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:33:22: error: invalid conversion from '__int128' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'} [-fpermissive]
   33 |         int n,k;cin>>n>>k;
      |                      ^
      |                      |
      |                      __int128
/usr/