Language: C++

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

int main() {
    int n;
    cin >> n;
    vector<pair<long double, long double>> c(n);
    long double sum = 0.0;
    long double p = 1.0;
    for (int i = 0; i < n; i++) {
        cin >> c.at(i).first >> c.at(i).second;
        p *= (i+1);
    }
    sort(c.begin(), c.end());
    do {
        for (int i = 1; i < n; i++) {
            sum += sqrt(pow((c.at(i-1).first-c.at(i).first), 2.0) + pow((c.at(i-1).second-c.at(i).second), 2.0));
        }
    } while (sqrt(c.begin(), c.end()));

    cout << fixed << setprecision(15) << sum / p << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:19:18: error: no matching function for call to 'sqrt(std::vector<std::pair<long double, long double> >::iterator, std::vector<std::pair<long double, long double> >::iterator)'
   19 |     } while (sqrt(c.begin(), c.end()));
      |              ~~~~^~~~~~~~~~~~~~~~~~~~
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:458:5: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_UnClos<std::_Sqrt, std::_ValArray, _Tp>, _Tp> std::sqrt(const valarray<_Tp>&)'
  458 |     _DEFINE_EXPR_UNARY_FUNCTION(sqrt, struct std::_Sqrt)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:458:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/valarray_after.h:458:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_UnClos<std::_Sqrt, std::_Expr, _Dom>, typename _Dom::value_type> std::sqrt(const _Expr<_Dom1, typename _Dom1::value_type>&)'
  458 |     _DEFINE_EXPR_UNARY_FUNCTION(sqrt, struct std::_Sqrt)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:458:5: 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:1195:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::sqrt(const complex<_Tp>&)'
 1195 |     sqrt(const complex<_Tp>& __z) { return __complex_sqrt(__z.__rep()); }
      |     ^~~~
/usr/include/c++/14/complex:1195:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:114:
/usr/include/c++/14/cmath:454:5: note: candidate: 'template<class _Tp> constexpr typename __gnu_cxx::__enable_if<std::__is_integer<_Tp>::__value, double>::__type std::sqrt(_Tp)'
  454 |     sqrt(_Tp __x)
      |     ^~~~
/usr/include/c++/14/cmath:454:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/features.h:523,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/c++config.h:683,
                 from /usr/include/c++/14/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:33:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:176:1: note: candidate: 'double sqrt(double)'
  176 | __MATHCALL (sqrt,, (_Mdouble_ __x));
      | ^~~~~~~~~~
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:176:1: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/cmath:446:3: note: candidate: 'constexpr long double std::sqrt(long double)'
  446 |   sqrt(long double __x)
      |   ^~~~
/usr/include/c++/14/cmath:446:3: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/cmath:442:3: note: candidate: 'constexpr float std::sqrt(float)'
  442 |   sqrt(float __x)
      |   ^~~~
/usr/include/c++/14/cmath:442:3: note:   candidate expects 1 argument, 2 provided