Problem p02647 (C++)

Buggy submission (status: Time Limit Exceeded):
#pragma region header
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rev(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define rev1(i, n) for (int i = (int)(n); i > 0; i--)
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define resort(v) sort((v).rbegin(), (v).rend())
#define vi vector<int>
#define vvi vector<vector<int>>
#define vc vector<char>
#define vvc vector<vector<char>>
#define vb vector<bool>
#define vvb vector<vector<bool>>
using ll = long long;
using P = pair<int, int>;
/* ----------------よく使う数字や配列----------------- */
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
constexpr ll mod = 1e9 + 7;
constexpr int inf = INT32_MAX / 2;
constexpr ll INF = LLONG_MAX / 2;
constexpr long double eps = DBL_EPSILON;
constexpr long double pi = 3.141592653589793238462643383279;
/* ----------------------end----------------------- */

/* --------------------テンプレート------------------ */
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;
}
/* ----------------------end----------------------- */

/* --------------------ライブラリ-------------------- */
ll fact(int i) { // 階乗
  if (i == 0)
    return 1;
  return (fact(i - 1)) * i % mod;
}
ll gcd(ll a, ll b) { // 最大公約数
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { // 最小公倍数
  return a * b / gcd(a, b);
}
int keta(ll n) { // 桁数を求める
  if (n == 0)
    return 1;
  int count = 0;
  while (n != 0) {
    n /= 10;
    count++;
  }
  return count;
}
ll ketasum(ll n) { // 各桁の和
  ll sum = 0;
  while (n != 0) {
    sum += n % 10;
    n /= 10;
  }
  return sum;
}
/* ----------------------end----------------------- */
#pragma endregion
signed main() {
  int n, k;
  cin >> n >> k;
  vi a(n);
  // vi table(n);
  vi set(n, 0);
  rep(i, n) {
    cin >> a[i];
    /*table[max(i-a[i],0LL)]++;
    table[min(i+a[i],n-1)]--;
    if(i>0) table[i]+=table[i-1];*/
  }
  rep(j, k) {
    if (j > 0)
      a = set;
    fill(set.begin(), set.end(), 0);
    rep(i, n) {
      set[max(i - a[i], 0LL)]++;
      if (i + a[i] < n - 1)
        set[i + a[i] + 1]--;

      // cout << set[i] << ' ';
    }
    rep1(i, n - 1) set[i] += set[i - 1];
    // for(int i = )
    // for(auto p:set) cout << p << ' ';cout << endl;
  }
  for (auto p : set)
    cout << p << ' ';
  return 0;
}

Fixed submission:
#pragma region header
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rev(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define rev1(i, n) for (int i = (int)(n); i > 0; i--)
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define resort(v) sort((v).rbegin(), (v).rend())
#define vi vector<int>
#define vvi vector<vector<int>>
#define vc vector<char>
#define vvc vector<vector<char>>
#define vb vector<bool>
#define vvb vector<vector<bool>>
using ll = long long;
using P = pair<int, int>;
/* ----------------よく使う数字や配列----------------- */
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
constexpr ll mod = 1e9 + 7;
constexpr int inf = INT32_MAX / 2;
constexpr ll INF = LLONG_MAX / 2;
constexpr long double eps = DBL_EPSILON;
constexpr long double pi = 3.141592653589793238462643383279;
/* ----------------------end----------------------- */

/* --------------------テンプレート------------------ */
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;
}
/* ----------------------end----------------------- */

/* --------------------ライブラリ-------------------- */
ll fact(int i) { // 階乗
  if (i == 0)
    return 1;
  return (fact(i - 1)) * i % mod;
}
ll gcd(ll a, ll b) { // 最大公約数
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { // 最小公倍数
  return a * b / gcd(a, b);
}
int keta(ll n) { // 桁数を求める
  if (n == 0)
    return 1;
  int count = 0;
  while (n != 0) {
    n /= 10;
    count++;
  }
  return count;
}
ll ketasum(ll n) { // 各桁の和
  ll sum = 0;
  while (n != 0) {
    sum += n % 10;
    n /= 10;
  }
  return sum;
}
/* ----------------------end----------------------- */
#pragma endregion
signed main() {
  int n, k;
  cin >> n >> k;
  vi a(n);
  // vi table(n);
  vi set(n, 0);
  rep(i, n) {
    cin >> a[i];
    /*table[max(i-a[i],0LL)]++;
    table[min(i+a[i],n-1)]--;
    if(i>0) table[i]+=table[i-1];*/
  }
  chmin(k, 1000LL);
  rep(j, k) {
    if (j > 0)
      a = set;
    fill(set.begin(), set.end(), 0);
    rep(i, n) {
      set[max(i - a[i], 0LL)]++;
      if (i + a[i] < n - 1)
        set[i + a[i] + 1]--;

      // cout << set[i] << ' ';
    }
    rep1(i, n - 1) set[i] += set[i - 1];
    // for(int i = )
    // for(auto p:set) cout << p << ' ';cout << endl;
  }
  for (auto p : set)
    cout << p << ' ';
  return 0;
}