Problem p02585 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;

//////////////////

#ifdef DEBUG
#include "debug.h"
#define dump(...)                                                              \\
  DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                              \\
          << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl  \\
          << "    ",                                                           \\
      dump_func(__VA_ARGS__)
#else
#define dump(...)
#endif

// http://beet-aizu.hatenablog.com/entry/2018/04/08/145516
template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }

template <typename T, typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}

template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}

//////////////////

#define int long long

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)

#define YES puts("YES")
#define Yes puts("Yes")
#define NO puts("NO")
#define No puts("No")
#define ALL(v) (v).begin(), (v).end()
int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

/*
#define mod 1000000007 /*/
#define mod 998244353 //*/

typedef pair<int, int> P;
#define INF (1LL << 60)

void solve() {
  int N, K;
  cin >> N >> K;
  vector<int> P(N);
  vector<int> C(N);
  rep(i, N) {
    int p;
    cin >> p;
    p--;
    P[i] = p;
  }
  rep(i, N) cin >> C[i];

  set<int> s;
  rep(i, N) s.insert(i);

  int ans = -INF;
  while (!s.empty()) {
    int now = *s.begin();
    vector<int> arr;
    while (s.find(now) != s.end()) {
      arr.push_back(C[now]);
      s.erase(now);
      now = P[now];
    }
    dump(arr);
    int kosu = arr.size();

    // 2倍に
    rep(i, kosu) arr.push_back(arr[i]);

    vector<int> sum(kosu * 2 + 1, 0);
    rep(i, kosu * 2) sum[i + 1] = sum[i] + arr[i];

    int wa = -INF;
    if (K <= kosu) {
      for (int i = 0; i < kosu; i++) {
        for (int l = 1; l <= K; l++) {
          wa = max(wa, sum[i + l] - sum[i]);
        }
      }
    } else {
      int cycle = K / kosu;
      int amari = K % kosu;

      if (sum[kosu] > 0) {
        for (int i = 0; i < kosu; i++) {
          for (int l = 1; l <= amari; l++) {
            wa = max(wa, sum[i + l] - sum[i]);
          }
        }
        if (amari == 0)
          wa = 0;
        wa += sum[kosu] * cycle;
      } else {
        for (int i = 0; i < kosu; i++) {
          for (int l = 1; l <= amari; l++) {
            wa = max(wa, sum[i + l] - sum[i]);
          }
        }
        if (amari == 0)
          wa = max(0LL, *max_element(ALL(arr)));
      }

      cycle--;
      amari = kosu;
      int wa2 = -INF;
      if (sum[kosu] > 0) {
        for (int i = 0; i < kosu; i++) {
          for (int l = 1; l <= amari; l++) {
            wa2 = max(wa2, sum[i + l] - sum[i]);
          }
        }
        if (amari == 0)
          wa2 = 0;
        wa2 += sum[kosu] * cycle;
      } else {
        for (int i = 0; i < kosu; i++) {
          for (int l = 1; l <= amari; l++) {
            wa2 = max(wa2, sum[i + l] - sum[i]);
          }
        }
        if (amari == 0)
          wa2 = max(0LL, *max_element(ALL(arr)));
      }
      chmax(wa, wa2);
    }
    chmax(ans, wa);
  }
  cout << ans << endl;
}

signed main() {
  cout << fixed << setprecision(18);
  cerr << fixed << setprecision(18);
  solve();
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

//////////////////

#ifdef DEBUG
#include "debug.h"
#define dump(...)                                                              \\
  DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                              \\
          << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl  \\
          << "    ",                                                           \\
      dump_func(__VA_ARGS__)
#else
#define dump(...)
#endif

// http://beet-aizu.hatenablog.com/entry/2018/04/08/145516
template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }

template <typename T, typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}

template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}

//////////////////

#define int long long

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)

#define YES puts("YES")
#define Yes puts("Yes")
#define NO puts("NO")
#define No puts("No")
#define ALL(v) (v).begin(), (v).end()
int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

/*
#define mod 1000000007 /*/
#define mod 998244353 //*/

typedef pair<int, int> P;
#define INF (1LL << 60)

void solve() {
  int N, K;
  cin >> N >> K;
  vector<int> P(N);
  vector<int> C(N);
  rep(i, N) {
    int p;
    cin >> p;
    p--;
    P[i] = p;
  }
  rep(i, N) cin >> C[i];

  set<int> s;
  rep(i, N) s.insert(i);

  int ans = -INF;
  while (!s.empty()) {
    int now = *s.begin();
    vector<int> arr;
    while (s.find(now) != s.end()) {
      arr.push_back(C[now]);
      s.erase(now);
      now = P[now];
    }
    dump(arr);
    int kosu = arr.size();

    // 2倍に
    rep(i, kosu) arr.push_back(arr[i]);

    vector<int> sum(kosu * 2 + 1, 0);
    rep(i, kosu * 2) sum[i + 1] = sum[i] + arr[i];

    int wa = *max_element(ALL(arr));
    if (K <= kosu) {
      for (int i = 0; i < kosu; i++) {
        for (int l = 1; l <= K; l++) {
          wa = max(wa, sum[i + l] - sum[i]);
        }
      }
    } else {
      assert(false);
      int cycle = K / kosu;
      int amari = K % kosu;
      for (int i = 0; i < kosu; i++) {
        for (int l = 1; l <= amari; l++) {
          wa = max(wa, sum[i + l] - sum[i]);
        }
      }
      if (sum[kosu] > 0) {
        if (amari == 0)
          wa = 0;
        wa += sum[kosu] * cycle;
      }
    }
    chmax(ans, wa);
  }
  cout << ans << endl;
}

signed main() {
  cout << fixed << setprecision(18);
  cerr << fixed << setprecision(18);
  solve();
}