Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i)=0; (i)<(n); (i)++)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define ll long long
#define pp pair<int,int> 
#define v(T) vector<T>
#define Yes cout << "Yes" << endl
#define No cout << "No" << endl
const int INF = 1001001001;
//int 2×10の9乗
//vector<vector<int>> a(n, vector<int>(m));
  //rep(i,n) rep(j,m) cin >> a[i][j]; 
//cout << fixed << setprecision(10);
//int gcd(int x, int y){
  //if(y==0) return x;
  //return gcd(y, x%y);
//}
//sort小さい順
 
int main(){
  int n,k;
  cin >> n >> k;
  v(int) x(n);
  rep(i,n) cin>>x[i];
  int ans=0;
  rep(i,n){
    if(x[i+k-1]<0) ans=abs(x[i]);
    if(x[i]<0 && x[i+k-1]>=0) ans=abs(x[i])+x[i+k-1]+min(abs(x[i],x[i+k-1]));
    else ans=x[i+k-1];
  }
  cout<<ans<<endl;
}    

Compiler output:
a.cc: In function 'int main()':
a.cc:29:61: error: no matching function for call to 'abs(__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type&, __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type&)'
   29 |     if(x[i]<0 && x[i+k-1]>=0) ans=abs(x[i])+x[i+k-1]+min(abs(x[i],x[i+k-1]));
      |                                                          ~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/bits/valarray_after.h:445:5: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_UnClos<std::_Abs, std::_ValArray, _Tp>, _Tp> std::abs(const valarray<_Tp>&)'
  445 |     _DEFINE_EXPR_UNARY_FUNCTION(abs, struct std::_Abs)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:445:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/valarray_after.h:445:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_UnClos<std::_Abs, std::_Expr, _Dom>, typename _Dom::value_type> std::abs(const _Expr<_Dom1, typename _Dom1::value_type>&)'
  445 |     _DEFINE_EXPR_UNARY_FUNCTION(abs, struct std::_Abs)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:445:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:892:5: note: candidate: 'template<class _Tp> _Tp std::abs(const complex<_Tp>&)'
  892 |     abs(const complex<_Tp>& __z) { return __complex_abs(__z.__rep()); }
      |     ^~~
/usr/include/c++/14/complex:892:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/cstdlib:79,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:42:
/usr/include/stdlib.h:980:12: note: candidate: 'int abs(int)'
  980 | extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur;
      |            ^~~
/usr/include/stdlib.h:980:12: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/cstdlib:81:
/usr/include/c++/14/bits/std_abs.h:137:3: note: candidate: 'constexpr __float128 std::abs(__float128)'
  137 |   abs(__float128 __x)
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:137:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:85:3: note: candidate: 'constexpr __int128 std::abs(__int128)'
   85 |   abs(__GLIBCXX_TYPE_INT_N_0 __x) { return __x >= 0 ? __x : -__x; }
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:85:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:79:3: note: candidate: 'constexpr long double std::abs(long double)'
   79 |   abs(long double __x)
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:79:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:75:3: note: candidate: 'constexpr float std::abs(float)'
   75 |   abs(float __x)
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:75:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:71:3: note: candidate: 'constexpr double std::abs(double)'
   71 |   abs(double __x)
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:71:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:61:3: note: candidate: 'long long int std::abs(long long int)'
   61 |   abs(long long __x) { return __builtin_llabs (__x); }
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:61:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/std_abs.h:56:3: note: candidate: 'long int std::abs(long int)'
   56 |   abs(long __i) { return __builtin_labs(__i); }
      |   ^~~
/usr/include/c++/14/bits/std_abs.h:56:3: note:   candidate expects 1 argument, 2 provided