Language: C++

#include <bits/stdc++.h>
#define INF 1000000000
#define LINF 1000000000000000000
#define MOD 1000000007
#define mod 998244353
#define INF63 1061109567
#define INF127 9187201950435737471
#define UINF 18446744073709551615
#define F first
#define S second
#define ll long long
#define N 5010
using namespace std;
ll n,k,p[N],c[N];
bool vis[N];
ll mxsum(vector<ll> x,ll ed,ll tp)
{
	ll i,mx=0;
	if(tp==0)
	{
		mx=-LINF;
	}
	for(i=0;i<ed;i++)
	{
		mx=max(mx,x[i]);
	}
	return mx;
}
ll fdmax(ll st)
{
	ll i,sc=0,mx=-LINF;
	vector<ll> sum;
	memset(vis,false,sizeof(vis));
	for(i=st;!vis[i];)
	{
		vis[i]=true;
		sc+=c[p[i]];
		sum.push_back(sc);
		mx=max(mx,sc);
		i=p[i];
	}
	if(k<sum.size())
	{
		return mxsum(sum,k,0);
	}
	return max(mx,sc*(k/sum.size())+mxsum(sum,k%sum.size(),1));
}
int main(){
	ll i,ans=-LINF;
	scanf("%lld%lld",&n,&k);
	for(i=1;i<=n;i++)
	{
		scanf("%lld",&p[i]);
	}
	for(i=1;i<=n;i++)
	{
		scanf("%lld",&c[i]);
	}
	for(i=1;i<=n;i++)
	{
		ans=max(ans,fdmax(i));
	}
	printf("%lld\n",ans);
	return 0;
}

Compiler output:
a.cc: In function 'long long int fdmax(long long int)':
a.cc:46:19: error: no matching function for call to 'max(long long int&, long long unsigned int)'
   46 |         return max(mx,sc*(k/sum.size())+mxsum(sum,k%sum.size(),1));
      |                ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included 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_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:46:19: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   46 |         return max(mx,sc*(k/sum.size())+mxsum(sum,k%sum.size(),1));
      |                ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:46:19: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   46 |         return max(mx,sc*(k/sum.size())+mxsum(sum,k%sum.size(),1));
      |                ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~