Language: C++

 //
#include<bits/stdc++.h>

using namespace std;

#define PB push_back
#define f first
#define s second
#define what_is(x) cerr << #x << " is " << x << endl;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

const int INF = 1000000007;
int h, w, k;
int x1, y1;
int x2, y2;
int dr[] = {1, -1, 0, 0};
int dc[] = {0, 0, 1, -1};

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
    vector<string> arr(h);
    for(int i=0; i<h; i++)
    {
        cin >> arr[i];
    }
    vector<vector<int>> dist(h, vector<int>(w, INF));
    x1--; y1--; x2--; y2--;
    queue<pair<int, pii>> q;
    q.push({0, {x1, y1}});
    dist[x1][y1] = 0;
    while(!q.empty())
    {
        pair<int, pii> t = q.front();
        q.pop();
        int cost = t.f;
        int y = t.s.s, x = t.s.f;
        for(int i=0; i<4; i++)
        {
            for(int a=1; a<=k; a++)
            {
                int newx = x + dr[i] * a;
                int newy = y + dc[i] * a;
                if(newx < 0 || newx >= h || newy < 0 || newy >= w)
                    break;
                int ncost = cost + 1;
                if(arr[newx][newy] == '@')
                    break;
                if(dist[newx][newy] > ncost)
                {
                    dist[newx][newy] = ncost;
                    q.push({ncost, {newx, newy}});
                }
                else if(dist[newx][newy] == ncost)
                    continue;
                else
                    break;
            }
        }
    }
    if(dist[x2][y2] == INF)
    {
        cout << -1;
    }
    else
    {
        cout << dist[x2][y2];
    }
    return 0;
}


Compiler output:
a.cc:17:9: error: 'int y1' redeclared as different kind of entity
   17 | int x1, y1;
      |         ^~
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:2:
/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:25:30: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   25 |     cin >> h >> w >> k >> 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:25:33: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   25 |     cin >> h >> w >> k >> 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |                                 double (*)(double) noexcept
a.cc:25:33: 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:25:33: 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]
   25 |     cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                 ^~
      |                                 |
      |