Language: C++

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define all(x) (x).begin(), (x).end()

using namespace __gnu_pbds;
using namespace std;

using ull = unsigned long long;
using ll = long long;
using ld = long double;
template <typename T> using ordered_set = tree<T, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update>;

const int mod = 1e9 + 7;
const int inf = INT_MAX;
const int N = 5000 + 5;

int n, k, p[N], c[N];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> p[i];
    for (int i = 1; i <= n; i++) cin >> c[i];

    ll ans = LLONG_MIN;
    for (int i = 1; i <= n; i++) {
        int pos = p[i];
        ll sum = c[i];

        vector<ll> vals = {sum};
        while (pos != i) {
            sum += c[pos];
            pos = p[pos];
            vals.push_back(sum);
        }

        ll cur = (k / vals.size()) * sum;
        for (int j = 0; j < k % vals.size(); j++) {
            cur = max(cur, (k / vals.size()) * sum + vals[j]);
        }

        if (k >= vals.size()) {
            for (int j = 0; j < vals.size(); j++) {
                cur = max(cur, (k / vals.size() - 1) * sum + vals[j]);
            }
        }

        for (int j = 0; j < min(k, (int)vals.size()); j++) {
            cur = max(cur, vals[j]);
        }
        ans = max(ans, cur);
    }

    cout << ans << "\n";
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:41:22: error: no matching function for call to 'max(ll&, long long unsigned int)'
   41 |             cur = max(cur, (k / vals.size()) * sum + vals[j]);
      |                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:41:22: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   41 |             cur = max(cur, (k / vals.size()) * sum + vals[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:
/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:41:22: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   41 |             cur = max(cur, (k / vals.size()) * sum + vals[j]);
      |                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:46:26: error: no matching function for call to 'max(ll&, long long unsigned int)'
   46 |                 cur = max(cur, (k / vals.size() - 1) * sum + vals[j]);
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:46:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   46 |                 cur = max(cur, (k / vals.size() - 1) * sum + vals[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
/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:46:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   46 |                 cur = max(cur, (k / vals.size() - 1) * sum + vals[j]);
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~