Language: C++

#ifdef __GNUG__
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <cmath>
#include <iomanip>
#include <functional>
#endif

//#pragma optimize GCC("O3")
typedef long long ll;
typedef long double ld;
using namespace std;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	ll n, k;
	cin >> n >> k;
	vector<ll>p(n), c(n);
	for (int i = 0; i < n; i++)
	{
		cin >> p[i];
		p[i]--;
	}
	for (int i = 0; i < n; i++)
		cin >> c[i];
	vector<vector<ll> > kam(n, vector<ll>(1));
	vector<vector<ll> > val(n, vector<ll>(1, 0));
	for (int i = 0; i < n; i++)
		kam[i][0] = i;
	ll ans = c.back();
	for (int i = 0; i < n; i++)
	{
		for (int j = 1; j <= n; j++)
		{
			val[i].push_back(val[i][j - 1] + c[p[kam[i][j - 1]]]);
			kam[i].push_back(p[kam[i][j - 1]]);
			if (kam[i][j] == i) break;
		}
		ll cely = max(0ll, val[i].back());
		for (ll j = 1; j < val[i].size(); j++)
		{
			if (k < j) break;
			ans = max(ans, (k - j) / (kam[i].size() - 1) * cely + val[i][j]);
		}
	}
	cout << ans << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:52:34: error: no matching function for call to 'max(ll&, long long unsigned int)'
   52 |                         ans = max(ans, (k - j) / (kam[i].size() - 1) * cely + val[i][j]);
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/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:52:34: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   52 |                         ans = max(ans, (k - j) / (kam[i].size() - 1) * cely + val[i][j]);
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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,
                 from a.cc:3:
/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:52:34: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   52 |                         ans = max(ans, (k - j) / (kam[i].size() - 1) * cely + val[i][j]);
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~