Language: C++

#include<bits/stdc++.h>
#pragma GCC target ("avx2")
#pragma GCC optimization ("Ofast")
#pragma GCC optimization ("unroll-loops")
#pragma comment(linker, "/stack:200000000")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;

typedef pair<int,int>pi;
typedef vector<int>vi;

const int MAXN=2000005;
const int MOD=1000000007;

#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define DEC(i,a,b) for(int i=(a);i>=(b);i--)
#define pb push_back
#define mp make_pair
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(),(v).end()
#define db(x) cerr<<#x<<" = "<<x<<"\n"
#define LOW(v,x) (lower_bound(all(v),(x))-(v).begin())
#define UP(v,x) (upper_bound(all(v),(x))-(v).begin())
struct state{
	int x, y, dir, streak, dist;
	state (int _x=0, int _y=0, int _dir=0, int _streak=0, int _dist=0): x(_x), y(_y), dir(_dir), streak(_streak), dist(_dist) {}
};

int H,W,K,x1,y1,x2,y2;
int dx[] = {1,-1,0,0};
int dy[] = {0,0,1,-1};
bool visited[MAXN][4];

main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin>>H>>W>>K;
	cin>>x1>>y1>>x2>>y2;
	
	char grid[H+1][W+1];
	FOR(i,1,H) FOR(j,1,W) cin>>grid[i][j];
	deque<state> q; 
	q.push_front(state(x1,y1,0,0,0));
	//q.push_front(state(2,4,0,1,0));
	while(!q.empty()){
		state cur = q.front();
		q.pop_front();
		//for (auto i:q) cout<<i.dist<<" ";
		//cout<<"\n";
		if (visited[cur.x + cur.y * (H+1)][cur.dir]) continue;
		visited[cur.x + cur.y * (H+1)][cur.dir] = 1;
		//db(cur.x), db(cur.y), db(cur.dist), db(cur.dir), db(cur.streak);
		//cout<<"---------------\n";
		
		if(cur.x == x2 && cur.y==y2){
			cout<<cur.dist<<"\n";
			exit(0);
		}
		FOR(i,0,3){
			int nx = cur.x + dx[i];
			int ny = cur.y + dy[i];
			if (nx > H || nx < 1 || ny > W || ny < 1) continue;
			if (grid[nx][ny] == '@') continue;
			if (i==cur.dir && cur.streak < K){
				q.push_front(state(nx,ny,i,cur.streak+1,cur.dist));
			}
			else{
				q.push_back(state(nx,ny,i,1,cur.dist+1));
			}
		}
	}
	cout<<-1;
}


Compiler output:
a.cc:29:14: error: 'int y1' redeclared as different kind of entity
   29 | int H,W,K,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:34:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   34 | main(){
      | ^~~~
a.cc: In function 'int main()':
a.cc:38:16: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   38 |         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:38:18: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   38 |         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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   38 |         cin>>x1>>y1>>x2>>y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:38:18: 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:38:18: 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]
   38 |         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:38:18: error: invalid conversion from 'double (*)(double) noexcept' to '