Language: C++

#include<bits/stdc++.h>
#define N 200005
using namespace std;
int x1,y1,x2,y2;
int n;
struct node
{
    int x,y;
    friend bool operator < (const node &aa,const node &bb)
    {
        return aa.y<bb.y;
    }
}a[N];
int f[N];
const double pi = 3.1415926535897932384626;
int main()
{
    cin>>x1>>y1>>x2>>y2;
    if(y1>y2)swap(y1,y2),swap(x1,x2);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%d%d",&a[i].x,&a[i].y);
    sort(a+1,a+n+1);
    double ans=abs(y2-y1)+abs(x2-x1);ans*=100;
    int len;
    if(x1<=x2)
    {

        len=0;f[0]=0;
        for(int i=1;i<=n;i++)
        {
            if(a[i].y>=y1&&a[i].y<=y2&&a[i].x>=x1&&a[i].x<=x2)
            {
                if(a[i].x>=f[len])f[++len]=a[i].y;
                else
                {
                    int l=1,r=len;
                    while(l<r)
                    {
                        int mid=(l+r)>>1;
                        if(a[i].x<f[mid])r=mid;
                        else l=mid+1;
                    }
                    f[l]=a[i].x;
                }
            }
        }
    }
    else
    {
        len=0;f[0]=0x3f3f3f3f;
        for(int i=1;i<=n;i++)
        {
            if(a[i].y>=y1&&a[i].y<=y2&&a[i].x>=x2&&a[i].x<=x1)
            {
                if(a[i].x<=f[len])f[++len]=a[i].y;
                else
                {
                    int l=1,r=len;
                    while(l<r)
                    {
                        int mid=(l+r)>>1;
                        if(a[i].x>f[mid])r=mid;
                        else l=mid+1;
                    }
                    f[l]=a[i].x;
                }
            }
        }
    }
    ans-=len*20;ans+=len*5*pi;
    if(len==min(abs(y2-y1),abs(x2-x1))+1)ans+=5*pi;
    printf("%.14lf\n",ans);
    return 0;
}


Compiler output:
a.cc:4:8: error: 'int y1' redeclared as different kind of entity
    4 | 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:18:12: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   18 |     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:18:14: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   18 |     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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:18:14: 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:18:14: 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]
   18 |     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:18:14: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'} [-fpermissive]
   18 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
/usr/include/c++/14/istream:133:7: