Language: C++

#include<iostream>
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define IO ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
int n, m, k,x1,x2,y1,y2;
vector<vector<char> > a;
vector<vector<int> > dis;
set<int> row[1000009], col[1000009];
queue<pair<int,int> > q;
void del(int x, int y)
{
    row[x].erase(y);
    col[y].erase(x);
    q.push({x,y});
}
void solveR(int x, int y)
{
    while(1)
    {
        auto it=row[x].lower_bound(y);
        if(it==row[x].end()||(*it-y)>k)
            break;
        int newy=*it;
        if(a[x][newy]=='@')
            break;
        dis[x][newy]=dis[x][y]+1;
        del(x,newy);
    }
}
void solveL(int x, int y)
{
    while(1)
    {
        auto it=row[x].lower_bound(y);
        if(it==row[x].begin())
            break;
        it--;
        if((y-*it)>k)
            break;
        int newy=*it;
        if(a[x][newy]=='@')
            break;
        dis[x][newy]=dis[x][y]+1;
        del(x,newy);
    }
}
void solveU(int x, int y)
{
    while(1)
    {
        auto it=col[y].lower_bound(x);
        if(it==col[y].begin())
            break;
        it--;
        if((x-*it)>k)
            break;
        int newx=*it;
       // cout<<newx<<" "<<y<<endl;
        if(a[newx][y]=='@')
            break;
        dis[newx][y]=dis[x][y]+1;
        del(newx,y);
    }
}
void solveD(int x, int y)
{
    while(1)
    {
        auto it=col[y].lower_bound(x);
        if(it==col[y].end()||(*it-x)>k)
            break;
        int newx=*it;
        if(a[newx][y]=='@')
            break;
        dis[newx][y]=dis[x][y]+1;
        del(newx,y);
    }
}
int main()
{
    IO
    cin>>n>>m>>k;
    cin>>x1>>y1>>x2>>y2;
    a.resize(n+9,vector<char>(m+9));
    dis.resize(n+9,vector<int>(m+9, 100000000));

    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
        {
            cin>>a[i][j];
            row[i].insert(j);
            col[j].insert(i);
        }

    dis[x1][y1]=0;
    del(x1,y1);
    while(!q.empty())
    {
        pair<int,int> node=q.front();
        q.pop();
        solveR(node.first,node.second);
        solveL(node.first,node.second);
        solveU(node.first,node.second);
        solveD(node.first,node.second);

    }
    if(dis[x2][y2]>1e7)
        dis[x2][y2]=-1;
    cout<<dis[x2][y2];
}


Compiler output:
a.cc:7:19: error: 'int y1' redeclared as different kind of entity
    7 | int n, m, k,x1,x2,y1,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/bits/requires_hosted.h:31,
                 from /usr/include/c++/14/iostream:38,
                 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:85:12: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   85 |     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/iostream:42:
/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:85:14: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   85 |     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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
a.cc:85:14: 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:85:14: 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]
   85 |     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:85:14: 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]
   85 |     cin>>x1>>y1>>x2>>y2;
      |              ^~
      |              |
      |              double (*)(double) noexcept
/usr/include/c++/14/istream:133:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = cha