Language: C++

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

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned __int128 HASH;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll,int> plli;
typedef pair<double, int> pdbi;
typedef pair<int,pii> pipii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n);i>0;i--)
#define rrep2(i,a,b) for (int i=(a);i>b;i--)
#define pb push_back
#define fi first
#define se second
#define all(a) (a).begin(),(a).end()

const ll mod = 1000000000 + 7;
const ll hmod1 = 999999937;
const ll hmod2 = 1000000000 + 9;
const ll INF = 1<<30;
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1, 1, 1, 0, 0, -1, -1, -1};
const int dy8[8] = {0, 1, -1, 1, -1, 0, 1, -1};
const long double pi = 3.141592653589793;

int x1, y1, x2, y2;
int n;
pair<int, int> xy[200000 + 5];
vector<pair<int, int>> hs;
vector<int> sy;

class BIT {
    public:
        int size;
        vector<int> node;

        BIT(int n, long long init_num) {
            size = n;
            for (int i = 0; i <= size; i++){
                node.pb(init_num);
            }
        }

        void add(int i, long long x) {
            while (i <= size) {
                node[i] += x;
                i += i & -i;
            }
        }

        long long sum(int i) {
            long long ret = 0;
            while (i > 0) {
                ret += node[i];
                i -= i & -i;
            }
            return ret;
        }

        long long range_sum(int l, int r) {
            return sum(r) - sum(l - 1);
        }
};

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> x1 >> y1 >> x2 >> y2;
    if (x1 > x2) {
        swap(x1, x2);
        swap(y1, y2);
    }
    //cout << x1 << y1 <<" "<< x2 << y2 << endl;
    cin >> n;
    rep(i, n) {
        cin >> xy[i].fi >> xy[i].se;
    }
    sort(xy, xy + n);
    int lx = 1e9;
    int rx = -1;
    rep(i, n) {
        if (x1 <= xy[i].fi && xy[i].fi <= x2) {
            lx = min(lx, i);
            rx = max(rx, i);
        }
    }
    //cout << lx << rx << endl;

    int cnt = 0;
    if (y1 <= y2) {
        rep2(i, lx, rx + 1) {
            //cout << xy[i].se << endl;
            if (y1 <= xy[i].se && xy[i].se <= y2) {
                sy.push_back(xy[i].se);
                hs.push_back(xy[i]);
            }
        }
        sort(all(sy));
        int size = hs.size();
        BIT bit(size + 1, 0);
        rep(i, size) {
            //cout << hs[i].fi <<" " << hs[i].se<<  endl;
            int idx = lower_bound(all(sy), hs[i].se) - sy.begin();
            idx++;
            //cout << idx << endl;
            bit.add(idx, 1);
            cnt = max(cnt, bit.sum(idx));
        }
    }
    else {
        rep2(i, lx, rx + 1) {
            if (y2 <= xy[i].se && xy[i].se <= y1) {
                sy.push_back(xy[i].se);
                hs.push_back(xy[i]);
            }
        }
        sort(all(sy));
        int size = hs.size();
        BIT bit(size + 1, 0);
        rep(i, size) {
            //cout << hs[i].fi <<" " << hs[i].se<<  endl;
            int idx = lower_bound(all(sy), hs[i].se) - sy.begin();
            idx++;
            //cout << idx << endl;
            bit.add(idx, 1);
            cnt = max(cnt, bit.sum(size) - bit.sum(idx - 1));
        }
    }
    long double ans = (abs(x2 - x1) + abs(y2 - y1)) * 100.0;
    //cout << cnt << endl;
    ans -= cnt *  20.0;
    if (x1 == x2 || y1 == y2) ans += cnt * 10.0 * pi;
    else ans += cnt * 5.0 * pi;
    cout << fixed << setprecision(13) << ans << endl;

}


Compiler output:
a.cc:39:9: error: 'long long int y1' redeclared as different kind of entity
   39 | int x1, y1, x2, y2;
      |         ^~
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,
                 from a.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:257:1: note: previous declaration 'double y1(double)'
  257 | __MATHCALL (y1,, (_Mdouble_));
      | ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:81:15: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |     ~~~~~~~~~ ^~ ~~
      |         |        |
      |         |        double(double) noexcept
      |         std::basic_istream<char>::__istream_type {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:
/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:81:18: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(short int)y1' to 'short int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(short unsigned int)y1' to 'short unsigned int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(int)y1' to 'int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(unsigned int)y1' to 'unsigned int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(long int)y1' to 'long int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(long unsigned int)y1' to 'long unsigned int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(long long int)y1' to 'long long int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(long long unsigned int)y1' to 'long long unsigned int&'
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:81:18: error: cannot bind rvalue '(void*)y1' 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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   81 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
/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:81:18: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__