Language: C++

#include<bits/stdc++.h>
using namespace std;
//# define pair<int,int>  pi
int get(vector<vector<int> >& g,int i, vector<int>& vis,vector<int>& dp)
{  int n=g.size();
   dp[i]=0;
  for(auto& k:g[i])
  {
     if(vis[k]==0)
     get(g,k,vis,dp);
    
  dp[i]=max(dp[i],dp[k]+1);
    
    
}
 
  
 
}
int main()
{
  int n,m;
  cin>>n>>m;
  int k1,k2;
  vector<vector<int> > g(n+1);
  for(int i=0;i<m;i++)
  { cin>>k1>>k2;
   g[k1].push_back(k2);
   }
  int max1=INT_MIN;
  int c;
 vector<bool> vis(n+1,false);
 vector<int> dp(n+1,0);
  for(int i=1;i<=n;i++)
  { if(vis[i]==false)
    get(g,i,vis,dp);
   
  }
  
 int d=*max_element(dp.begin(),dp.end());
   cout<<d;
  
}


Compiler output:
a.cc: In function 'int get(std::vector<std::vector<int> >&, int, std::vector<int>&, std::vector<int>&)':
a.cc:19:1: warning: no return statement in function returning non-void [-Wreturn-type]
   19 | }
      | ^
a.cc: In function 'int main()':
a.cc:36:8: error: no matching function for call to 'get(std::vector<std::vector<int> >&, int&, std::vector<bool>&, std::vector<int>&)'
   36 |     get(g,i,vis,dp);
      |     ~~~^~~~~~~~~~~~
a.cc:4:5: note: candidate: 'int get(std::vector<std::vector<int> >&, int, std::vector<int>&, std::vector<int>&)'
    4 | int get(vector<vector<int> >& g,int i, vector<int>& vis,vector<int>& dp)
      |     ^~~
a.cc:4:53: note:   no known conversion for argument 3 from 'std::vector<bool>' to 'std::vector<int>&'
    4 | int get(vector<vector<int> >& g,int i, vector<int>& vis,vector<int>& dp)
      |                                        ~~~~~~~~~~~~~^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_pair.h:1250:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(pair<_Tp1, _Tp2>&)'
 1250 |     get(pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1250:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1255:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(pair<_Tp1, _Tp2>&&)'
 1255 |     get(pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1255:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1260:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(const pair<_Tp1, _Tp2>&)'
 1260 |     get(const pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1260:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1265:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(const pair<_Tp1, _Tp2>&&)'
 1265 |     get(const pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1265:5: note:   candidate expects 1 argument, 4 provided
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/tuple:2445:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >& std::get(tuple<_Elements ...>&)'
 2445 |     get(tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2445:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2451:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >& std::get(const tuple<_Elements ...>&)'
 2451 |     get(const tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2451:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2457:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >&& std::get(tuple<_Elements ...>&&)'
 2457 |     get(tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2457:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2466:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >&& std::get(const tuple<_Elements ...>&&)'
 2466 |     get(const tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2466:5: note:   candidate expects 1 argument, 4 provided
In file included from /usr/include/c++/14/functional:65,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53:
/usr/include/c++/14/array:390:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp& std::get(array<_Tp, _Nm>&)'
  390 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:390:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/array:399:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp&& std::get(array<_Tp, _Nm>&&)'
  399 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:399:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/array:408:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp& std::get(const array<_Tp, _Nm>&)'
  408 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:408:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/array:417:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp&& std::get(const array<_Tp, _Nm>&&)'
  417 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:417:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1272:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(pair<_T1, _T2>&)'
 1272 |     get(pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1272:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1277:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const pair<_T1, _T2>&)'
 1277 |     get(const pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1277:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1282:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(pair<_T1, _T2>&&)'
 1282 |     get(pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1282:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1287:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const pair<_T1, _T2>&&)'
 1287 |     get(const pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1287:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1292:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(pair<_Up, _Tp>&)'
 1292 |     get(pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1292:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1297:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const pair<_Up, _Tp>&)'
 1297 |     get(const pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1297:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1302:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(pair<_Up, _Tp>&&)'
 1302 |     get(pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1302:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/bits/stl_pair.h:1307:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const pair<_Up, _Tp>&&)'
 1307 |     get(const pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1307:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2476:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__enable_if_t<(__i >= sizeof... (_Types))> std::get(const tuple<_Elements ...>&)' (deleted)
 2476 |     get(const tuple<_Elements...>&) = delete;
      |     ^~~
/usr/include/c++/14/tuple:2476:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2483:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp& std::get(tuple<_Elements ...>&)'
 2483 |     get(tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2483:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2494:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp&& std::get(tuple<_Elements ...>&&)'
 2494 |     get(tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2494:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2505:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp& std::get(const tuple<_Elements ...>&)'
 2505 |     get(const tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2505:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/tuple:2517:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp&& std::get(const tuple<_Elements ...>&&)'
 2517 |     get(const tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2517:5: note:   candidate expects 1 argument, 4 provided
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:80:
/usr/include/c++/14/variant:1715:5: note: candidate: 'template<long unsigned int _Np, class ... _Types> constexpr std::variant_alternative_t<_Np, std::variant<_Types ...> >& std::get(variant<_Types ...>&)'
 1715 |     get(variant<_Types...>& __v)
      |     ^~~
/usr/include/c++/14/variant:1715:5: note:   candidate expects 1 argument, 4 provided
/usr/include/c++/14/variant:1726:5: note: candidate: 'template<long