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

#include <algorithm>
#include <bitset>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;
using vll = vector<long long>;
using sll = set<long long>;

template <typename T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

template <typename T> map<T, T> getPrimeFactor(T n) {
  map<T, T> res;
  for (T i = 2; i * i <= n; ++i) {
    while (n % i == 0) {
      res[i]++;
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}

template <typename T> bool IsPrimeNumber(T num) {
  if (num <= 2)
    return true;
  else if (num % 2 == 0)
    return false;

  double sqrtNum = sqrt(num);
  for (int i = 3; i <= sqrtNum; i += 2) {
    if (num % i == 0) {
      return false;
    }
  }

  return true;
}

long long modinv(long long a, long long m) {
  long long b = m, u = 1, v = 0;
  while (b) {
    long long t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  u %= m;
  if (u < 0)
    u += m;
  return u;
}

#define rep(i, s, e) for (ll i = s; i < e; i++)
#define repeq(i, s, e) for (ll i = s; i <= e; i++)

int main() {
  ll N, K;
  std::cin >> N >> K;

  vll A(N);
  vll sum(N + 1, 0);
  rep(i, 0, N) {
    std::cin >> A[i];
    sum[max(i - A[i], 0LL)]++;
    sum[min(i + A[i] + 1, N)]--;
  }

  rep(i, 0, K) {
    ll cnt = 0;
    vll tmp(N + 1, 0);
    rep(j, 0, N) {
      cnt += sum[j];
      A[j] = cnt;

      tmp[max(j - A[j], 0LL)]++;
      tmp[min(j + A[j] + 1, N)]--;
    }

    if (sum == tmp) {
      break;
    }
    sum = tmp;
  }
  rep(i, 0, N) {
    std::cout << A[i];
    if (i < N - 1) {
      std::cout << " ";
    }
  }
  std::cout << endl;

  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;
using vll = vector<long long>;
using sll = set<long long>;

template <typename T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

template <typename T> map<T, T> getPrimeFactor(T n) {
  map<T, T> res;
  for (T i = 2; i * i <= n; ++i) {
    while (n % i == 0) {
      res[i]++;
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}

template <typename T> bool IsPrimeNumber(T num) {
  if (num <= 2)
    return true;
  else if (num % 2 == 0)
    return false;

  double sqrtNum = sqrt(num);
  for (int i = 3; i <= sqrtNum; i += 2) {
    if (num % i == 0) {
      return false;
    }
  }

  return true;
}

long long modinv(long long a, long long m) {
  long long b = m, u = 1, v = 0;
  while (b) {
    long long t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  u %= m;
  if (u < 0)
    u += m;
  return u;
}

#define rep(i, s, e) for (ll i = s; i < e; i++)
#define repeq(i, s, e) for (ll i = s; i <= e; i++)

int main() {
  ll N, K;
  std::cin >> N >> K;

  vll A(N);
  vll sum(N + 1, 0);
  rep(i, 0, N) {
    std::cin >> A[i];
    sum[max(i - A[i], 0LL)]++;
    sum[min(i + A[i] + 1, N)]--;
  }

  rep(i, 0, K) {
    ll cnt = 0;
    vll tmp(N + 1, 0);
    rep(j, 0, N) {
      cnt += sum[j];
      A[j] = cnt;
      tmp[max(j - A[j], 0LL)]++;
      tmp[min(j + A[j] + 1, N)]--;
    }
    sum = tmp;
  }
  rep(i, 0, N) {
    std::cout << A[i];
    if (i < N - 1) {
      std::cout << " ";
    }
  }
  std::cout << endl;

  return 0;
}