Language: C++

#include<bits/stdc++.h>
#include<string.h>
#include<vector>
#include<set>
#include<map>
#include<stack>
#include<queue>
#define endl  "\n"
#define ll long long
#define int long long
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cin.exceptions(cin.failbit);cout.tie(NULL);
using namespace std;
bool isPrime(int n)
{
    if (n <= 1)
        return false;
    if (n <= 3)
        return true;
    if (n % 2 == 0 || n % 3 == 0)
        return false;
    for (int i = 5; i * i <= n; i += 6)
    {
        if ((n % i == 0) || (n % (i + 2) == 0))
            return false;
    }
    return true;
}
int n,m,x1,y1,x2,y2;
char a[1005][1005];
vector<int> v;
int vis[1005][1005];
int valid(int x,int y)
{
	if(x<n && x>=0 && y<m && y>=0)
	return 1;
	else
	return 0;
}


dfs(int x,int y,int ans)
{
	
	if(x==x2 && y==y2)
	{
		v.push_back(ans);
		return 0;
	}
	
	
	int flag=0;
	if(valid(x-1,y) && vis[x-1][y]==0 && a[x-1][y]=='.')
	{
		flag=1;
		vis[x-1][y]=1;
		dfs(x-1,y,ans);
	}
	
	
	if(valid(x,y-1) && vis[x][y-1]==0 && a[x][y-1]=='.')
	{
		flag=1;
		vis[x][y-1]=1;
		dfs(x,y-1,ans);
	}
	
	if(valid(x+1,y) && vis[x+1][y]==0 && a[x+1][y]=='.')
	{
		flag=1;
		vis[x+1][y]=1;
		dfs(x+1,y,ans);
	}
	
	
	if(valid(x,y+1) && vis[x][y+1]==0 && a[x][y+1]=='.')
	{
		flag=1;
		vis[x][y+1]=1;
		dfs(x,y+1,ans);
	}
	
	if(flag==0)
	{
		int final=0;
		
		int temp=x-2;
		int temp2=y-2;
		int var=x+2;
		int var2=y+2;
		
		
		for(int i=temp;i<=var;i++)
		{
			for(int j=temp2;j<=var2;j++)
			{
				if(i==x && y==j)
				continue;
				
				if(valid(i,j) && vis[i][j]==0 && a[i][j]=='.')
				{
					final=1;
					//ans++;
					vis[i][j]=1;
					dfs(i,j,ans+1);
				}
			}
		}
		
		if(final==0)
		{	
			ans=INT_MIN;
		}
		
	}
	
	
}


int32_t main()
{
	int t;
	t=1;
	while(t--)
	{
		
		
		
		cin >> n >> m >> x1 >> y1 >> x2 >> y2;
		x1--;
		y1--;
		x2--;
		y2--;
		
		for(int i=0;i<n;i++)
		{
			for(int j=0;j<m;j++)
			{
				cin >> a[i][j];
				vis[i][j]=0;
			}
		}
		
		dfs(x1,y1,0);
		
		int mn=INT_MAX;
		for(int i=0;i<v.size();i++)
		{
			
			//cout << v[i] << " ";
			if(v[i]>=0)
			{
				mn=min(mn,v[i]);
			}
		}
		
		if(mn==INT_MAX)
		cout << "-1";
		else
		cout << mn;
		
		
	}
}




Compiler output:
a.cc:28:12: error: 'long long int y1' redeclared as different kind of entity
   28 | int n,m,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:41:1: error: ISO C++ forbids declaration of 'dfs' with no type [-fpermissive]
   41 | dfs(int x,int y,int ans)
      | ^~~
a.cc: In function 'int32_t main()':
a.cc:129:37: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
  129 |                 cin >> n >> m >> 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:129:40: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
  129 |                 cin >> n >> m >> 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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:129:40: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
  129 |                 cin >> n >> m >> x1 >> y1 >> x2 >> y2;
      |                                        ^~
      |                                        |
      |                                        double (*)(double) noexcept
a.cc:129:40: 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