Language: C++

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

#define int long long
#define ll long long
#define pb push_back
#define mp make_pair
#define f(i,a,n) for(int i=a ; i<n ; i++)
#define rf(i,n,a) for(int i=n ; i>=a ; i--)
#define F first
#define S second
#define all(c) (c).begin(),(c).end()
#define sz(v) (int)(v).size()
#define fast ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)

typedef long double ld;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef pair<pii,int> ppi;
typedef vector<pii> vpi;

const int inf = 1e9;
const int inf64 = 1e18;
const int MOD = inf + 7;

map<pii,bool> vis;
map<pii,pii> par;

int h,w,k;
int x1,y1,x2,y2;
vector<vector<char>> c;

void dfs(int x , int y , int px = -1 , int py = -1){
   if(x <= 0 || y <= 0 || x > h || y > w || vis[{x,y}] || c[x][y] == '@') return ;
   par[{x,y}] = {px,py};
   vis[{x,y}] = true;
   dfs(x+1 , y , x , y);
   dfs(x-1 , y , x , y);
   dfs(x , y-1 , x , y);
   dfs(x , y+1 , x , y);
}

int32_t main(){
   fast;
   cin >> h >> w >> k;

   cin >> x1 >> y1 >> x2 >> y2;

   c.resize(h+1 , vector<char>(w+1));

   f(i,1,h+1) f(j,1,w+1) cin >> c[i][j];
   dfs(x1,y1);

   if(!vis[{x2,y2}]){
      cout << -1 << "\n";
      return 0;
   }


   vpi path;
   pii node = {x2,y2};
   pii cmp = {-1,-1};
   while(node != cmp){
      path.pb(node);
      node = par[node];
   }

   for(auto p : path)  cout << p.F << " " << p.S << "\n";
   vi v;
   
   // f(i,1,sz(path)-1){
   //    int x1 = path[i-1].F , y1 = path[i-1].F;
   //    int x2 = path[i].F , y2 = path[i].F;
   //    int x3 = path[i+1].F , y3 = path[i+1].F;

   // }
   // :<

   f(i,1,sz(path)){
      auto p = path[i-1];
      auto q = path[i];
      if(p.F == q.F && p.S + 1 == q.S) v.pb(0);
      if(p.F == q.F && p.S - 1 == q.S) v.pb(1);
      if(p.F + 1 == q.F && p.S == q.S) v.pb(2);
      if(p.F - 1 == q.F && p.S == q.S) v.pb(3);
   }

   int ans = 0;
   for(int i=0 ; i<sz(v) ; i++){
      int cnt = 0;
      int j = i;
      while(j < sz(v) && v[j] == v[i]) cnt++,j++;

      if(cnt > 1){
         i = j - 1;
      }
      ans += (cnt + k - 1)/k;
   }

   cout << ans << "\n";
}

Compiler output:
a.cc:30:8: error: 'long long int y1' redeclared as different kind of entity
   30 | 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 'int32_t main()':
a.cc:47:14: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   47 |    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:47:17: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   47 |    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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   47 |    cin >> x1 >> y1 >> x2 >> y2;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
a.cc:47:17: 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:47:17: 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]
   47 |    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:47:17: 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