Language: C++

/*⠄⢰⣧⣼⣯⠄⣸⣠⣶⣶⣦⣾⠄⠄⠄⠄⡀⠄⢀⣿⣿⠄⠄⠄⢸⡇⠄⠄
⠄⠄⠄⣾⣿⠿⠿⠶⠿⢿⣿⣿⣿⣿⣦⣤⣄⢀⡅⢠⣾⣛⡉⠄⠄⠄⠸⢀⣿⠄
⠄⠄⢀⡋⣡⣴⣶⣶⡀⠄⠄⠙⢿⣿⣿⣿⣿⣿⣴⣿⣿⣿⢃⣤⣄⣀⣥⣿⣿⠄
⠄⠄⢸⣇⠻⣿⣿⣿⣧⣀⢀⣠⡌⢻⣿⣿⣿⣿⣿⣿⣿⣿⣿⠿⠿⠿⣿⣿⣿⠄
⠄⢀⢸⣿⣷⣤⣤⣤⣬⣙⣛⢿⣿⣿⣿⣿⣿⣿⡿⣿⣿⡍⠄⠄⢀⣤⣄⠉⠋⣰
⠄⣼⣖⣿⣿⣿⣿⣿⣿⣿⣿⣿⢿⣿⣿⣿⣿⣿⢇⣿⣿⡷⠶⠶⢿⣿⣿⠇⢀⣤
⠘⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣽⣿⣿⣿⡇⣿⣿⣿⣿⣿⣿⣷⣶⣥⣴⣿⡗
⢀⠈⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡟⠄
⢸⣿⣦⣌⣛⣻⣿⣿⣧⠙⠛⠛⡭⠅⠒⠦⠭⣭⡻⣿⣿⣿⣿⣿⣿⣿⣿⡿⠃⠄
⠘⣿⣿⣿⣿⣿⣿⣿⣿⡆⠄⠄⠄⠄⠄⠄⠄⠄⠹⠈⢋⣽⣿⣿⣿⣿⣵⣾⠃⠄
⠄⠘⣿⣿⣿⣿⣿⣿⣿⣿⠄⣴⣿⣶⣄⠄⣴⣶⠄⢀⣾⣿⣿⣿⣿⣿⣿⠃⠄⠄
⠄⠄⠈⠻⣿⣿⣿⣿⣿⣿⡄⢻⣿⣿⣿⠄⣿⣿⡀⣾⣿⣿⣿⣿⣛⠛⠁⠄⠄⠄
⠄⠄⠄⠄⠈⠛⢿⣿⣿⣿⠁⠞⢿⣿⣿⡄⢿⣿⡇⣸⣿⣿⠿⠛⠁⠄⠄⠄⠄⠄
⠄⠄⠄⠄⠄⠄⠄⠉⠻⣿⣿⣾⣦⡙⠻⣷⣾⣿⠃⠿⠋⠁⠄⠄⠄⠄⠄⢀⣠⣴
⣿⣿⣿⣶⣶⣮⣥⣒⠲⢮⣝⡿⣿⣿⡆⣿⡿⠃⠄⠄⠄⠄⠄⠄⠄⣠⣴⣿*/

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define iiii pair<ii,ii>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl;

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

ll MAX(ll a){return a;}
ll MIN(ll a){return a;}
template<typename... Args>
ll MAX(ll a,Args... args){return max(a,MAX(args...));}
template<typename... Args>
ll MIN(ll a,Args... args){return min(a,MIN(args...));}

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

const int dx[]={1,-1,0,0};
const int dy[]={0,0,1,-1};

int n,m,k;
int x1,y1,x2,y2;
string grid[1000005];

ii w[4][1000005];

priority_queue<iiii,vector<iiii>,greater<iiii> > pq;

int node(int i,int j){
	return i*m+j;
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	memset(w,63,sizeof(w));
	
	cin>>n>>m>>k;
	cin>>x1>>y1>>x2>>y2;
	x1--,y1--,x2--,y2--;
	
	rep(x,0,n){
		cin>>grid[x];
	}
	
	rep(z,0,4){
		w[z][node(x1,y1)]=ii(0,0);
		pq.push(iiii(w[z][node(x1,y1)],ii(z,node(x1,y1))));
	}
	
	while (!pq.empty()){
		ii weight=pq.top().fi;
		int pz=pq.top().se.fi,px=pq.top().se.se/m,py=pq.top().se.se%m;
		pq.pop();
		
		if (w[pz][node(px,py)]!=weight) continue;
		//cout<<pz<<" "<<px<<" "<<py<<endl;
		//cout<<weight.fi<<" "<<weight.se<<endl;
		
		rep(z,0,4){
			int xx=px+dx[z],yy=py+dy[z];
			if (xx<0 || n<=xx || yy<0 || m<=yy) continue;
			if (grid[xx][yy]=='@') continue;
			
			ii temp;
			if (pz==z){
				temp=weight;
				temp.se++;
			}
			else{
				temp=ii(weight.fi+(weight.se!=0),1);
			}
			
			if (temp.se==k) temp=ii(temp.fi+1,0);
			
			if (w[z][node(xx,yy)]>temp){
				w[z][node(xx,yy)]=temp;
				pq.push(iiii(w[z][node(xx,yy)],ii(z,node(xx,yy))));
			}
		}
	}
	
	ll ans=1e18;
	rep(z,0,4){
		ans=min(ans,w[z][node(x2,y2)].fi+(w[z][node(x2,y2)].se!=0));
	}
	
	if (ans==1e18) cout<<"-1"<<endl;
	else cout<<ans<<endl;
	
}


Compiler output:
a.cc:52:8: error: 'int y1' redeclared as different kind of entity
   52 | 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:17:
/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:71:16: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   71 |         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:71:18: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   71 |         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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   71 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:71:18: 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:71:18: 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]
   71 |         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:71:18: 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