Problem p02647 (C++) — buggy submission, verdict: Time Limit Exceeded

#pragma region head
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repp(i, a, b) for (int i = a; i <= (b); ++i)
#define repr(i, a, b) for (int i = a; i >= (b); --i)
#define bit(n) (1LL << (n))
#define len(x) ((ll)(x).size())
#define debug(var) cout << "[" << #var << "]\\n" << var << endl
#define test(s)                                                                \\
  if (!(s))                                                                    \\
    cout << "Line " << __LINE__ << ": [" << #s << "] is false" << endl;
#define int long long
typedef long long ll;
#define double long double
typedef double ld;
const int INF = 1001001001001001001ll;
const ll LINF = 1001001001001001001ll;
const int MOD = 1000000007;
const double EPS = 1e-9;
const double PI = acos(-1.0);

template <typename T> ostream &operator<<(ostream &s, const vector<T> &v) {
  int len = v.size();
  for (int i = 0; i < len; ++i) {
    s << v[i];
    if (i < len - 1)
      s << ' ';
  }
  return s;
}

template <typename T>
ostream &operator<<(ostream &s, const vector<vector<T>> &vv) {
  int len = vv.size();
  for (int i = 0; i < len; ++i) {
    s << vv[i];
    if (i != len - 1)
      s << '\\n';
  }
  return s;
}

template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

__attribute__((constructor)) void initial() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
#pragma endregion

signed main() {
  int N, K;
  cin >> N >> K;
  vector<int> A(N);
  rep(i, N) { cin >> A[i]; }

  chmin(K, 50ll);

  while (K-- > 0) {
    vector<int> imos(N + 1);
    rep(i, N) {
      int l = max(0ll, i - A[i]);
      int r = min(i + A[i] + 1, N);
      imos[l]++, imos[r]--;
    }

    int temp = 0;
    rep(i, N) {
      temp += imos[i];
      A[i] = temp;
    }
  }
  cout << A << endl;
}

Error: TLE

Fixed submission:

#pragma region head
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repp(i, a, b) for (int i = a; i <= (b); ++i)
#define repr(i, a, b) for (int i = a; i >= (b); --i)
#define bit(n) (1LL << (n))
#define len(x) ((ll)(x).size())
#define debug(var) cout << "[" << #var << "]\\n" << var << endl
#define test(s)                                                                \\
  if (!(s))                                                                    \\
    cout << "Line " << __LINE__ << ": [" << #s << "] is false" << endl;
#define int long long
typedef long long ll;
#define double long double
typedef double ld;
const int INF = 1001001001001001001ll;
const ll LINF = 1001001001001001001ll;
const int MOD = 1000000007;
const double EPS = 1e-9;
const double PI = acos(-1.0);

template <typename T> ostream &operator<<(ostream &s, const vector<T> &v) {
  int len = v.size();
  for (int i = 0; i < len; ++i) {
    s << v[i];
    if (i < len - 1)
      s << ' ';
  }
  return s;
}

template <typename T>
ostream &operator<<(ostream &s, const vector<vector<T>> &vv) {
  int len = vv.size();
  for (int i = 0; i < len; ++i) {
    s << vv[i];
    if (i != len - 1)
      s << '\\n';
  }
  return s;
}

template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

__attribute__((constructor)) void initial() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
#pragma endregion

signed main() {
  int N, K;
  cin >> N >> K;
  vector<int> A(N);
  rep(i, N) { cin >> A[i]; }

  chmin(K, 50ll);

  typedef pair<double, int> P;
  while (K-- > 0) {
    priority_queue<P, vector<P>, greater<P>> pq;
    rep(i, N) {
      pq.push(P(i - A[i] - EPS, 1));
      pq.push(P(i + A[i] + EPS, -1));
    }

    int temp = 0;
    rep(i, N) {
      while (!pq.empty() && pq.top().fi < i) {
        temp += pq.top().se;
        pq.pop();
      }
      A[i] = temp;
    }
  }
  cout << A << endl;
}