Problem p02585 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using V = vector<int>;
using Vll = vector<ll>;
using Vld = vector<ld>;
using Vbo = vector<bool>;
using VV = vector<V>;
using VVll = vector<Vll>;
using VVld = vector<Vld>;
using VVbo = vector<Vbo>;
using VVV = vector<VV>;
using VVVll = vector<VVll>;
using P = pair<int, int>;
using Pll = pair<ll, ll>;
using Pld = pair<ld, ld>;
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define all(a) (a).begin(), (a).end()
struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} fast_ios_;
template <typename T> inline int sz(T &x) { return x.size(); }
template <typename T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << '(' << p.first << ", " << p.second << ')';
  return os;
}
template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (auto &e : v)
    is >> e;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (auto &e : v)
    os << e << ' ';
  return os;
}
template <typename T> inline int count_between(vector<T> &a, T l, T r) {
  return lower_bound(all(a), r) - lower_bound(all(a), l);
} // [l, r)
inline int fLog2(const int x) {
  assert(x > 0);
  return 31 - __builtin_clz(x);
} // floor(log2(x))
inline int fLog2(const ll x) {
  assert(x > 0);
  return 63 - __builtin_clzll(x);
}
inline int cLog2(const int x) {
  assert(x > 0);
  return (x == 1) ? 0 : 32 - __builtin_clz(x - 1);
} // ceil(log2(x))
inline int cLog2(const ll x) {
  assert(x > 0);
  return (x == 1) ? 0 : 64 - __builtin_clzll(x - 1);
}
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
void fail() {
  cout << -1 << '\\n';
  exit(0);
}
// const int INF  = 1<<30;
const ll INFll = 1ll << 62;
// const ld EPS   = 1e-10;
// const ld PI    = acos(-1.0);
// const int MOD  = int(1e9)+7;
// const int MOD  = 998244353;

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

  ll ans = -INFll;
  rep(i, n) {
    Vll sc(n + 1);

    ll st = -1;

    int x = i;
    rep(j, n) {
      x = p[x];
      sc[j + 1] = sc[j] + c[x];

      if (x == i) {
        st = j + 1;
        break;
      }
    }

    ll sum = sc[st];
    ll m = k / st;

    ll per = 0;
    ll kk = k;
    if (sum > 0) {
      if (kk >= 2 * st) {
        per += sum * (m - 1);
        kk -= st * (m - 1);
      }
    } else
      kk = min(kk, n);

    x = i;
    ll res = per;
    rep(j, kk) {
      x = p[x];
      res += c[x];
      chmax(ans, res);
      // cout << res << ' ';
    }
    // cout << '\\n';
  }

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


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using V = vector<int>;
using Vll = vector<ll>;
using Vld = vector<ld>;
using Vbo = vector<bool>;
using VV = vector<V>;
using VVll = vector<Vll>;
using VVld = vector<Vld>;
using VVbo = vector<Vbo>;
using VVV = vector<VV>;
using VVVll = vector<VVll>;
using P = pair<int, int>;
using Pll = pair<ll, ll>;
using Pld = pair<ld, ld>;
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define all(a) (a).begin(), (a).end()
struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} fast_ios_;
template <typename T> inline int sz(T &x) { return x.size(); }
template <typename T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << '(' << p.first << ", " << p.second << ')';
  return os;
}
template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (auto &e : v)
    is >> e;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (auto &e : v)
    os << e << ' ';
  return os;
}
template <typename T> inline int count_between(vector<T> &a, T l, T r) {
  return lower_bound(all(a), r) - lower_bound(all(a), l);
} // [l, r)
inline int fLog2(const int x) {
  assert(x > 0);
  return 31 - __builtin_clz(x);
} // floor(log2(x))
inline int fLog2(const ll x) {
  assert(x > 0);
  return 63 - __builtin_clzll(x);
}
inline int cLog2(const int x) {
  assert(x > 0);
  return (x == 1) ? 0 : 32 - __builtin_clz(x - 1);
} // ceil(log2(x))
inline int cLog2(const ll x) {
  assert(x > 0);
  return (x == 1) ? 0 : 64 - __builtin_clzll(x - 1);
}
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
void fail() {
  cout << -1 << '\\n';
  exit(0);
}
// const int INF  = 1<<30;
const ll INFll = 1ll << 62;
// const ld EPS   = 1e-10;
// const ld PI    = acos(-1.0);
// const int MOD  = int(1e9)+7;
// const int MOD  = 998244353;

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

  ll ans = -INFll;
  rep(i, n) {
    Vll sc(n + 1);

    ll st = -1;

    rep(j, n) {
      int x = i;
      rep(j, n) {
        x = p[x];
        sc[j + 1] = sc[j] + c[x];

        if (x == i) {
          st = j + 1;
          break;
        }
      }
    }

    ll sum = sc[st];
    ll m = k / st;

    ll per = 0;
    ll kk = k;
    if (sum > 0) {
      if (kk >= 2 * st) {
        per += sum * (m - 1);
        kk -= st * (m - 1);
      }
    } else
      kk = min(kk, n);

    int x = i;
    ll res = per;
    rep(j, kk) {
      x = p[x];
      res += c[x];
      chmax(ans, res);
      // cout << res << ' ';
    }
    // cout << '\\n';
  }

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