Problem p02537 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
#define ll long long int
#define lld long double
#define pb push_back
#define pii pair<ll, ll>
#define mi map<ll, ll>
#define vec vector<ll>
#define all(a) (a).begin(), (a).end()
#define F first
#define S second
#define mod 1000000007
#define rep(i, a, b) for (ll i = a; i < b; i++)
#define repi(i, a, b) for (ll i = a; i <= b; i++)
#define per(i, a, b) for (ll i = a; i >= b; i--)
#define mp make_pair
#define mit map<ll, ll>::iterator
#define sit set<ll>::iterator
#define pit pair<ll, ll>::iterator
#define xxx exit(0);
#define tr(container, it)                                                      \
  for (__typeof(container.begin()) it = container.begin();                     \
       it != container.end(); it++)
using namespace std;
ll xo(ll x, ll y) { return (x | y) & (~x | ~y); }
ll bin_Expo(ll x, ll n) {
  if (x == 0)
    return 0;
  if (n == 0)
    return 1;
  else if (n % 2 == 0) // n is even
    return bin_Expo(x * x, n / 2);
  else // n is odd
    return x * bin_Expo(x * x, (n - 1) / 2);
}
ll mod_Expo(ll x, ll n, ll M) {
  if (x == 0)
    return 0;
  if (n == 0)
    return 1;
  else if (n % 2 == 0) // n is even
    return mod_Expo((x * x) % M, n / 2, M);
  else // n is odd
    return (x * mod_Expo((x * x) % M, (n - 1) / 2, M)) % M;
}
bool prime_check(ll x) {
  bool prime = (x >= 2);
  for (ll i = 2; i * i <= x; i++) {
    if (x % i == 0) {
      prime = false;
      break;
    }
  }
  return prime;
}
ll logg(ll base, ll x) { return (ll)(log(x) / log(base)); }
ll a[300005], dp[300005], n, k;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int TESTS = 1;
  //	cin>>TESTS;
  while (TESTS--) {
    ll m, i, j, l, h, w, q, ans, x, y;
    cin >> n >> k;
    rep(i, 0, n) cin >> a[i], dp[i] = 1;
    x = 1;
    rep(i, 1, n) {
      rep(j, 0, i) {
        if (abs(a[i] - a[j]) <= k)
          dp[i] = max(dp[i], dp[j] + 1);
      }
      x = max(x, dp[i]);
    }
    cout << x;
  }
  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
#define ll long long int
#define lld long double
#define pb push_back
#define pii pair<ll, ll>
#define mi map<ll, ll>
#define vec vector<ll>
#define all(a) (a).begin(), (a).end()
#define F first
#define S second
#define mod 1000000007
#define rep(i, a, b) for (ll i = a; i < b; i++)
#define repi(i, a, b) for (ll i = a; i <= b; i++)
#define per(i, a, b) for (ll i = a; i >= b; i--)
#define mp make_pair
#define mit map<ll, ll>::iterator
#define sit set<ll>::iterator
#define pit pair<ll, ll>::iterator
#define xxx exit(0);
#define tr(container, it)                                                      \
  for (__typeof(container.begin()) it = container.begin();                     \
       it != container.end(); it++)
using namespace std;
ll xo(ll x, ll y) { return (x | y) & (~x | ~y); }
ll bin_Expo(ll x, ll n) {
  if (x == 0)
    return 0;
  if (n == 0)
    return 1;
  else if (n % 2 == 0) // n is even
    return bin_Expo(x * x, n / 2);
  else // n is odd
    return x * bin_Expo(x * x, (n - 1) / 2);
}
ll mod_Expo(ll x, ll n, ll M) {
  if (x == 0)
    return 0;
  if (n == 0)
    return 1;
  else if (n % 2 == 0) // n is even
    return mod_Expo((x * x) % M, n / 2, M);
  else // n is odd
    return (x * mod_Expo((x * x) % M, (n - 1) / 2, M)) % M;
}
bool prime_check(ll x) {
  bool prime = (x >= 2);
  for (ll i = 2; i * i <= x; i++) {
    if (x % i == 0) {
      prime = false;
      break;
    }
  }
  return prime;
}
ll logg(ll base, ll x) { return (ll)(log(x) / log(base)); }
ll a[300005], dp[300005], n, k;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int TESTS = 1;
  //	cin>>TESTS;
  while (TESTS--) {
    ll m, i, j, l, h, w, q, ans, x, y;
    cin >> n >> k;
    rep(i, 0, n) cin >> a[i], dp[i] = 1;
    x = 1;
    rep(i, 1, n) {
      for (j = i - 1; j >= 0 && i - j <= 100; j--) {
        if (abs(a[i] - a[j]) <= k)
          dp[i] = max(dp[i], dp[j] + 1);
      }
      x = max(x, dp[i]);
    }
    cout << x;
  }
  return 0;
}