Problem p02647 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vb = vector<bool>;
using P = pair<ll, ll>;
template <typename T> using pq = priority_queue<T>;
template <typename T> using minpq = priority_queue<T, vector<T>, greater<T>>;
template <typename T, typename K> using ump = unordered_map<T, K>;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ll mod = 1000000007;
const ll inf = ll(1e9);
const ll e5 = ll(1e5);
const ll ll_inf = ll(1e9) * ll(1e9);

#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repr(i, n) for (ll i = ll(n - 1); i >= 0; i--)
#define each(i, mp) for (auto &i : mp)
#define eb emplace_back
#define F first
#define S second
#define all(obj) (obj).begin(), (obj).end()

template <class T> ostream &operator<<(ostream &out, const vector<T> &list) {
  ll n = list.size();
  rep(i, n) out << list[i] << ' ';
  return out;
}

template <class T> istream &operator>>(istream &in, vector<T> &list) {
  ll n = list.size();
  rep(i, n) in >> list[i];
  return in;
}

template <class T>
ostream &operator<<(ostream &out, const vector<vector<T>> &list) {
  ll n = list.size();
  rep(i, n) out << list[i] << '\\n';
  return out;
}

/* ------------- ANSWER ------------- */
/* ---------------------------------- */
// sample: http://beet-aizu.hatenablog.com/entry/2017/12/01/225955
// verified with
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_A
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_F
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_G
template <typename Data, typename Lazy> struct SegmentTree {
public:
  bool isLazy = false;
  int sz;
  vector<Data> seg;
  vector<Lazy> lazy;

  // mergeするときの操作
  using MergeData = function<Data(Data, Data)>;
  // lazyをxでupdate
  using UpdateLazyFromX = function<Lazy(Lazy, Lazy)>;
  // dataをlazyでupdate
  using UpdateDataFromLazy = function<Data(Data, Lazy)>;
  // lenが与えられた時にlazyを計算
  using CalcLazyWithLen = function<Lazy(Lazy, ll)>;

  // lazy
  // O(N)
  SegmentTree(int n, const MergeData fm, const UpdateLazyFromX fl,
              const UpdateDataFromLazy fa, const CalcLazyWithLen fw, Data M1,
              Lazy A1)
      : fm(fm), fl(fl), fa(fa), fw(fw), M1(M1), A1(A1) {
    isLazy = true;
    sz = 1;
    while (sz < n)
      sz *= 2;
    seg.assign(2 * sz - 1, M1);
    lazy.assign(2 * sz - 1, A1);
  }

  // not lazy
  SegmentTree(int n, const MergeData fm, Data M1)
      : fm(fm), M1(M1),
        // ここからdummy
        fl([M1](Data a, Data b) { return M1; }),
        fa([M1](Data a, Lazy b) { return M1; }),
        fw([M1](Lazy a, ll b) { return M1; }), A1(M1) {
    isLazy = false;
    sz = 1;
    while (sz < n)
      sz *= 2;
    seg.assign(2 * sz - 1, M1);
  }

  // not lazy
  // O(logN)
  Data update(int i, Data x) {
    i += sz - 1;
    seg[i] = x;
    while (i > 0) {
      i = (i - 1) / 2;
      seg[i] = fm(seg[2 * i + 1], seg[2 * i + 2]);
    }
  }

  void build(const vector<Data> &v) {
    ll n = v.size();
    rep(i, n) seg[i + sz - 1] = v[i];
    for (ll i = sz - 2; i >= 0; --i) {
      seg[i] = fm(seg[i * 2 + 1], seg[i * 2 + 2]);
    }
  }

  // for lazy only
  // O(logN)
  Data update(int a, int b, Data x) { return update(a, b, x, 0, 0, sz); }

  // O(logN)
  Data query(int a, int b) { return query(a, b, 0, 0, sz); }

private:
  const MergeData fm;
  const UpdateLazyFromX fl;
  const UpdateDataFromLazy fa;
  const CalcLazyWithLen fw;
  const Data M1;
  const Lazy A1;

  void eval(int len, int k) {
    if (lazy[k] == A1)
      return;
    if (k * 2 + 1 < sz * 2 - 1) {
      lazy[2 * k + 1] = fl(lazy[2 * k + 1], lazy[k]);
      lazy[2 * k + 2] = fl(lazy[2 * k + 2], lazy[k]);
    }
    seg[k] = fa(seg[k], fw(lazy[k], len));
    lazy[k] = A1;
  }

  Data update(int a, int b, Data x, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return seg[k];
    if (a <= l && r <= b) {
      lazy[k] = fl(lazy[k], x);
      return fa(seg[k], fw(lazy[k], r - l));
    }
    return seg[k] = fm(update(a, b, x, k * 2 + 1, l, (l + r) / 2),
                       update(a, b, x, k * 2 + 2, (l + r) / 2, r));
  }

  Data query(int a, int b, int k, int l, int r) {
    if (isLazy)
      eval(r - l, k);
    if (r <= a || b <= l)
      return M1;
    if (a <= l && r <= b)
      return seg[k];
    Data vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    Data vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return fm(vl, vr);
  }
};

SegmentTree<ll, ll> RangeMinimumTree(int n) {
  auto fm = [](ll a, ll b) { return min(a, b); };
  auto fl = [](ll a, ll b) { return b; };
  auto fa = [](ll a, ll b) { return b; };
  auto fw = [](ll a, ll w) { return a; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, LONG_MAX, LONG_MAX);
  return tree;
}

SegmentTree<ll, ll> RangeMaxTree(int n) {
  auto fm = [](ll a, ll b) { return max(a, b); };
  auto fl = [](ll a, ll b) { return b; };
  auto fa = [](ll a, ll b) { return b; };
  auto fw = [](ll a, ll w) { return a; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, 1, LONG_MIN);
  return tree;
}

SegmentTree<ll, ll> RangeSumTree(int n) {
  auto fm = [](ll a, ll b) { return a + b; };
  auto fl = [](ll a, ll b) { return a + b; };
  auto fa = [](ll a, ll b) { return a + b; };
  auto fw = [](ll a, ll w) { return a * w; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, 0, 0);
  return tree;
}

void solve() {
  ll n, k;
  cin >> n >> k;
  vl a(n);
  cin >> a;
  vl b(n);
  rep(n_k, k) {
    ll cnt = 0;
    vl imos(n + 1);
    rep(i, n) {
      ll val;
      if (n_k > 0)
        val = b[i];
      else
        val = a[i];
      if (val >= i && val >= n - 1 - i) {
        cnt++;
      }
      imos[max(0LL, i - val)]++;
      imos[min(n, i + val + 1)]--;
    }
    ll now = 0;
    rep(i, n) {
      now += imos[i];
      b[i] = now;
    }
    if (cnt == n) {
      rep(i, n) { cout << n << ' '; }
      cout << endl;
      return;
    }
  }
  rep(i, n) { cout << b[i] << ' '; }
  cout << endl;
}

int main() {
#ifdef MY_DEBUG
  while (true) {
#endif
    solve();
#ifdef MY_DEBUG
  }
#endif
  return 0;
}

Error: WA

Fixed submission:

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vb = vector<bool>;
using P = pair<ll, ll>;
template <typename T> using pq = priority_queue<T>;
template <typename T> using minpq = priority_queue<T, vector<T>, greater<T>>;
template <typename T, typename K> using ump = unordered_map<T, K>;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ll mod = 1000000007;
const ll inf = ll(1e9);
const ll e5 = ll(1e5);
const ll ll_inf = ll(1e9) * ll(1e9);

#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repr(i, n) for (ll i = ll(n - 1); i >= 0; i--)
#define each(i, mp) for (auto &i : mp)
#define eb emplace_back
#define F first
#define S second
#define all(obj) (obj).begin(), (obj).end()

template <class T> ostream &operator<<(ostream &out, const vector<T> &list) {
  ll n = list.size();
  rep(i, n) out << list[i] << ' ';
  return out;
}

template <class T> istream &operator>>(istream &in, vector<T> &list) {
  ll n = list.size();
  rep(i, n) in >> list[i];
  return in;
}

template <class T>
ostream &operator<<(ostream &out, const vector<vector<T>> &list) {
  ll n = list.size();
  rep(i, n) out << list[i] << '\\n';
  return out;
}

/* ------------- ANSWER ------------- */
/* ---------------------------------- */
// sample: http://beet-aizu.hatenablog.com/entry/2017/12/01/225955
// verified with
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_A
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_F
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_2_G
template <typename Data, typename Lazy> struct SegmentTree {
public:
  bool isLazy = false;
  int sz;
  vector<Data> seg;
  vector<Lazy> lazy;

  // mergeするときの操作
  using MergeData = function<Data(Data, Data)>;
  // lazyをxでupdate
  using UpdateLazyFromX = function<Lazy(Lazy, Lazy)>;
  // dataをlazyでupdate
  using UpdateDataFromLazy = function<Data(Data, Lazy)>;
  // lenが与えられた時にlazyを計算
  using CalcLazyWithLen = function<Lazy(Lazy, ll)>;

  // lazy
  // O(N)
  SegmentTree(int n, const MergeData fm, const UpdateLazyFromX fl,
              const UpdateDataFromLazy fa, const CalcLazyWithLen fw, Data M1,
              Lazy A1)
      : fm(fm), fl(fl), fa(fa), fw(fw), M1(M1), A1(A1) {
    isLazy = true;
    sz = 1;
    while (sz < n)
      sz *= 2;
    seg.assign(2 * sz - 1, M1);
    lazy.assign(2 * sz - 1, A1);
  }

  // not lazy
  SegmentTree(int n, const MergeData fm, Data M1)
      : fm(fm), M1(M1),
        // ここからdummy
        fl([M1](Data a, Data b) { return M1; }),
        fa([M1](Data a, Lazy b) { return M1; }),
        fw([M1](Lazy a, ll b) { return M1; }), A1(M1) {
    isLazy = false;
    sz = 1;
    while (sz < n)
      sz *= 2;
    seg.assign(2 * sz - 1, M1);
  }

  // not lazy
  // O(logN)
  Data update(int i, Data x) {
    i += sz - 1;
    seg[i] = x;
    while (i > 0) {
      i = (i - 1) / 2;
      seg[i] = fm(seg[2 * i + 1], seg[2 * i + 2]);
    }
  }

  void build(const vector<Data> &v) {
    ll n = v.size();
    rep(i, n) seg[i + sz - 1] = v[i];
    for (ll i = sz - 2; i >= 0; --i) {
      seg[i] = fm(seg[i * 2 + 1], seg[i * 2 + 2]);
    }
  }

  // for lazy only
  // O(logN)
  Data update(int a, int b, Data x) { return update(a, b, x, 0, 0, sz); }

  // O(logN)
  Data query(int a, int b) { return query(a, b, 0, 0, sz); }

private:
  const MergeData fm;
  const UpdateLazyFromX fl;
  const UpdateDataFromLazy fa;
  const CalcLazyWithLen fw;
  const Data M1;
  const Lazy A1;

  void eval(int len, int k) {
    if (lazy[k] == A1)
      return;
    if (k * 2 + 1 < sz * 2 - 1) {
      lazy[2 * k + 1] = fl(lazy[2 * k + 1], lazy[k]);
      lazy[2 * k + 2] = fl(lazy[2 * k + 2], lazy[k]);
    }
    seg[k] = fa(seg[k], fw(lazy[k], len));
    lazy[k] = A1;
  }

  Data update(int a, int b, Data x, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return seg[k];
    if (a <= l && r <= b) {
      lazy[k] = fl(lazy[k], x);
      return fa(seg[k], fw(lazy[k], r - l));
    }
    return seg[k] = fm(update(a, b, x, k * 2 + 1, l, (l + r) / 2),
                       update(a, b, x, k * 2 + 2, (l + r) / 2, r));
  }

  Data query(int a, int b, int k, int l, int r) {
    if (isLazy)
      eval(r - l, k);
    if (r <= a || b <= l)
      return M1;
    if (a <= l && r <= b)
      return seg[k];
    Data vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    Data vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return fm(vl, vr);
  }
};

SegmentTree<ll, ll> RangeMinimumTree(int n) {
  auto fm = [](ll a, ll b) { return min(a, b); };
  auto fl = [](ll a, ll b) { return b; };
  auto fa = [](ll a, ll b) { return b; };
  auto fw = [](ll a, ll w) { return a; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, LONG_MAX, LONG_MAX);
  return tree;
}

SegmentTree<ll, ll> RangeMaxTree(int n) {
  auto fm = [](ll a, ll b) { return max(a, b); };
  auto fl = [](ll a, ll b) { return b; };
  auto fa = [](ll a, ll b) { return b; };
  auto fw = [](ll a, ll w) { return a; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, LONG_MIN, LONG_MIN);
  return tree;
}

SegmentTree<ll, ll> RangeSumTree(int n) {
  auto fm = [](ll a, ll b) { return a + b; };
  auto fl = [](ll a, ll b) { return a + b; };
  auto fa = [](ll a, ll b) { return a + b; };
  auto fw = [](ll a, ll w) { return a * w; };
  SegmentTree<ll, ll> tree(n, fm, fl, fa, fw, 0, 0);
  return tree;
}

void solve() {
  ll n, k;
  cin >> n >> k;
  vl a(n);
  cin >> a;
  clock_t start = clock();
  SegmentTree<ll, ll> tree = RangeMaxTree(n + 1);
  rep(i, n + 1) tree.update(i, i + 1, 1);
  rep(n_k, k) {
    ll cnt = 0;
    SegmentTree<ll, ll> nxt = RangeSumTree(n + 1);
    rep(i, n) {
      ll val;
      if (n_k > 0)
        val = tree.query(i, i + 1);
      else
        val = a[i];
      if (val >= i && val >= n - 1 - i) {
        cnt++;
      }
      nxt.update(max(0LL, i - val), min(n, i + val + 1), 1);
    }
    if (cnt == n) {
      rep(i, n) { cout << n << ' '; }
      cout << endl;
      return;
    }
    rep(i, n) { tree.update(i, i + 1, nxt.query(i, i + 1)); }
    clock_t end = clock();

    const double time =
        static_cast<double>(end - start) / CLOCKS_PER_SEC * 1000.0;
    if (time > 1999) {
      throw runtime_error("mm");
    }
  }
  rep(i, n) { cout << tree.query(i, i + 1) << ' '; }
  cout << endl;
}

int main() {
#ifdef MY_DEBUG
  while (true) {
#endif
    solve();
#ifdef MY_DEBUG
  }
#endif
  return 0;
}