Language: C++

#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define zero_pad(num) setfill('0') << std::right << setw(num)
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;

int main() {
    ll n, k;
    cin >> n >> k;
    vector<ll> p(n), c(n);
    rep(i, n)cin >> p[i];
    rep(i, n)p[i]--;
    rep(i, n)cin >> c[i];

    ll INF = 1001001001001001001;
    ll ans = -INF;
    rep(i, n){
        
        vector<ll> cnt(n, INF);
        int idx = p[i];
        cnt[idx] = c[idx];
        int num = 1;
        while(idx != i){
            ll sum = cnt[idx];
            idx = p[idx];
            cnt[idx] = sum + c[idx];
            num++;
        }
        ll score = 0;
        ll kk = k;
        if(cnt[i] > 0){
            ll m = max(0, kk / num - 1);
            score += m * cnt[i];
            kk -= m;
        }else{
            if(kk % num == 0)kk = num;
            else kk %= num;
        }
        
        ll mx = -INF;
        idx = i;
        rep(j, kk){
            idx = p[idx];
            mx = max(mx, cnt[idx]);
        }
        if(kk > 0)score += mx;
        ans = max(ans, score);
    }
    cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:34:23: error: no matching function for call to 'max(int, ll)'
   34 |             ll m = max(0, kk / num - 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:34:23: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'll' {aka 'long long int'})
   34 |             ll m = max(0, kk / num - 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:34:23: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   34 |             ll m = max(0, kk / num - 1);
      |                    ~~~^~~~~~~~~~~~~~~~~