Language: C++

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

int main(){
	int N;
	cin >> N;
	vector<pair<int,int>> p;
	ll x,y;
	for(int i(0);i<N;++i){
		cin >> x >> y;
		p.push_back(make_pair(x,y));
	}
	long double ans(0);
	ll X(0),Y(0);
	for(int i(0);i<N;++i){
		if(p[i].first >= 0 && p[i].second >= 0){
			X += p[i].first;
			Y += p[i].second;
		}
	}
	ans = max(ans, sqrt(X*X+Y*Y));
	X = Y = 0;
	for(int i(0);i<N;++i){
		if(p[i].first >= 0 && p[i].second <= 0){
			X += p[i].first;
			Y += p[i].second;
		}
	}
	ans = max(ans, sqrt(X*X+Y*Y));
	X = Y = 0;
	for(int i(0);i<N;++i){
		if(p[i].first <= 0 && p[i].second >= 0){
			X += p[i].first;
			Y += p[i].second;
		}
	}
	ans = max(ans, sqrt(X*X+Y*Y));
	X = Y = 0;
	for(int i(0);i<N;++i){
		if(p[i].first <= 0 && p[i].second <= 0){
			X += p[i].first;
			Y += p[i].second;
		}
	}
	ans = max(ans, sqrt(X*X+Y*Y));
	cout << setprecision(30) << ans << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:22:18: error: no matching function for call to 'max(long double&, __gnu_cxx::__enable_if<true, double>::__type)'
   22 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:22:18: note:   deduced conflicting types for parameter 'const _Tp' ('long double' and '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'})
   22 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:22:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'long double'
   22 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
a.cc:30:18: error: no matching function for call to 'max(long double&, __gnu_cxx::__enable_if<true, double>::__type)'
   30 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:30:18: note:   deduced conflicting types for parameter 'const _Tp' ('long double' and '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'})
   30 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:30:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'long double'
   30 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
a.cc:38:18: error: no matching function for call to 'max(long double&, __gnu_cxx::__enable_if<true, double>::__type)'
   38 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:38:18: note:   deduced conflicting types for parameter 'const _Tp' ('long double' and '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'})
   38 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:38:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'long double'
   38 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
a.cc:46:18: error: no matching function for call to 'max(long double&, __gnu_cxx::__enable_if<true, double>::__type)'
   46 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:46:18: note:   deduced conflicting types for parameter 'const _Tp' ('long double' and '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'})
   46 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:46:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'long double'
   46 |         ans = max(ans, sqrt(X*X+Y*Y));
      |               ~~~^~~~~~~~~~~~~~~~~~~~