Language: C++

#include <cstdio>
#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <string>
#include <utility>
#include <queue>
#include <unordered_set>
#include <set>
#include <unordered_map>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
using namespace std;
#define sL(i) i << 1
#define sR(i) i << 1 | 1
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair<int,int> pi;
typedef pair<int, pair<int,int>> ppi;
const int MOD = 1e9 + 7;
const int INF = 2e9 + 5;

int h, w, k;
int x1, y1, x2, y2;
vector<string> grid;
vector<vector<int>> dist[4], rem[4], vis[4];

int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};
string D = "ESWN";

bool valid(int x, int y) {
    return 0 <= x && x < h && 0 <= y && y < w && grid[x][y] != '@';
}

int main() {
    cin.sync_with_stdio(0);
    cin.tie(0);
    cin >> h >> w >> k;
    cin >> x1 >> y1 >> x2 >> y2;
    --x1; --y1; --x2; --y2;
    grid.resize(h);
    for (int i = 0; i < h; i++) {
        cin >> grid[i];
    }
    for (int i = 0; i < 4; i++) {
        dist[i].resize(h, vector<int>(w, INF));
        rem[i].resize(h, vector<int>(w, 0));
        vis[i].resize(h, vector<int>(w, false));
    }

    deque<ppi> q;
    q.emplace_back(0, pi(x1, y1));
    dist[0][x1][y1] = 0;
    rem[0][x1][y1] = 0;
    while (!q.empty()) {
        int dir = q.front().first;
        int x = q.front().second.first;
        int y = q.front().second.second;
        q.pop_front();
        if (vis[dir][x][y]) continue;
        vis[dir][x][y] = true;
        int curdist = dist[dir][x][y];
        int currem = rem[dir][x][y];
        // cout << D[dir] << " (" << x + 1 << "," << y + 1 << ")" << " " << curdist << " " << currem << endl;
        for (int i = 0; i < 4; i++) {
            int nx = x + dx[i];
            int ny = y + dy[i];
            if (!valid(nx, ny)) continue;
            bool w = true;
            int ndist = curdist + 1;
            int nrem = k - 1;
            if (i == dir && currem > 0) {
                w = false;
                ndist = curdist;
                nrem = currem - 1;
            }
            if (ndist < dist[i][nx][ny] || 
                (ndist == dist[i][nx][ny] && rem[i][nx][ny] < nrem)) {
                dist[i][nx][ny] = ndist;
                rem[i][nx][ny] = nrem;
                if (w) {
                    q.emplace_back(i, pi(nx, ny));
                } else {
                    q.emplace_front(i, pi(nx, ny));
                }
            }
        }
    }
    int ans = INF;
    for (int i = 0; i < 4; i++) {
        ans = min(ans, dist[i][x2][y2]);
    }
    if (ans == INF) ans = -1;
    cout << ans;
}

Compiler output:
a.cc:28:9: error: 'int y1' redeclared as different kind of entity
   28 | 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/cstdio:41,
                 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:44:15: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   44 |     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,
                 from a.cc:2:
/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:44:18: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   44 |     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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:44:18: 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:44:18: 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]
   44 |     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:44:18: 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<char>&)'} [-fpermissive]
   44 |     cin >> x1 >> y1 >> x2 >> y2;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
/usr/includ