Language: C++

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

int main() {
  int N, S1 = 0, S2 = 0, lastTimeAbsolute;
  cin >> N;
  vector <int> W(N);

  for(int i = 0; i < N; i++) {
    cin >> W[i];
  }

  //重さの順にソート
  sort(W.begin(), W.end());

  for(int T = 0; T < N; T++) {
    for(int i = 0; i < N; i++) {
      if(i <= T) {
        S1 += W[i];
      } else {
        S2 += W[i];
      }
    }
    
    if(abs(S1, S2) == 0) {
      cout << 0 << endl;
      break;
    } else if(abs(S1, S2) < 0){
      cout << lastTimeAbsolute << endl;
      break;
    } else {
      lastTimeAbsolute = abs(S1, S2);
    }
  }

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:11: error: no matching function for call to 'abs(int&, int&)'
   25 |     if(abs(S1, S2) == 0) {
      |        ~~~^~~~~~~~
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
a.cc:28:18: error: no matching function for call to 'abs(int&, int&)'
   28 |     } else if(abs(S1, S2) < 0){
      |               ~~~^~~~~~~~
/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
/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
/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
/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
a.cc:32:29: error: no matching function for call to 'abs(int&, int&)'
   32 |       lastTimeAbsolute = abs(S1, S2);
      |                          ~~~^~~~~~~~
/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
/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
/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
/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