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

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
// #pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v)                                                         \\
  REP(i, v.size()) cout << v[i] << ((i == v.size() - 1) ? "\\n" : " ")
template <typename T1, typename T2> inline void chmin(T1 &a, T2 b) {
  if (a > b)
    a = b;
}
template <typename T1, typename T2> inline void chmax(T1 &a, T2 b) {
  if (a < b)
    a = b;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 1e9 + 7;
constexpr int MAX = 500050;
const double pi = acos(-1);
constexpr double EPS = 1e-8;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;

void test() {
  int n = 50;
  vector<int> A(n);
  REP(_, n) {
    print_space(A);
    vector<int> B(n);
    REP(i, n) {
      FOR(j, max(0LL, i - A[i]), min(n, i + A[i] + 1)) { B[j]++; }
    }
    A = B;
  }
}

void solve() {
  int N, K;
  cin >> N >> K;
  int n = N;
  vector<int> A(n);
  REP(i, N) cin >> A[i];
  vector<int> B(N);
  REP(_, min((ll)61, K)) {
    REP(i, N) B[i] = 0;
    REP(i, n) {
      int l = max(0LL, i - A[i]), r = min(n, i + A[i] + 1);
      B[l]++;
      if (r < n)
        B[r]--;
    }
    REP(i, n - 1) B[i + 1] += B[i];
    A = B;
  }
  print_space(A);
}

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  mt.seed((int)(time(0)));
  // REP(_, 10000)test();
  // int q;
  // cin >> q;
  // while (q--)
  solve();
}


Error: TLE

Fixed submission:

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
// #pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v)                                                         \\
  REP(i, v.size()) cout << v[i] << ((i == v.size() - 1) ? "\\n" : " ")
template <typename T1, typename T2> inline void chmin(T1 &a, T2 b) {
  if (a > b)
    a = b;
}
template <typename T1, typename T2> inline void chmax(T1 &a, T2 b) {
  if (a < b)
    a = b;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 1e9 + 7;
constexpr int MAX = 500050;
const double pi = acos(-1);
constexpr double EPS = 1e-8;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;

void test() {
  int n = 50;
  vector<int> A(n);
  REP(_, n) {
    print_space(A);
    vector<int> B(n);
    REP(i, n) {
      FOR(j, max(0LL, i - A[i]), min(n, i + A[i] + 1)) { B[j]++; }
    }
    A = B;
  }
}

void solve() {
  int N, K;
  cin >> N >> K;
  int n = N;
  vector<int> A(n);
  REP(i, N) cin >> A[i];
  REP(_, min((ll)100, K)) {
    vector<int> B(N);
    REP(i, n) {
      FOR(j, max(0LL, i - A[i]), min(n, i + A[i] + 1)) { B[j]++; }
    }
    A = B;
  }
  print_space(A);
}

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  mt.seed((int)(time(0)));
  // REP(_, 10000)test();
  // int q;
  // cin >> q;
  // while (q--)
  solve();
}