Problem:
 Score : 400 points    Problem Statement You are given a sequence A_1, A_2, ..., A_N and an integer K .  Print the maximum possible length of a sequence B that satisfies the following conditions:   B is a (not necessarily continuous) subsequence of A .  For each pair of adjacents elements of B , the absolute difference of the elements is at most K .       Constraints  1 \leq N \leq 300,000  0 \leq A_i \leq 300,000  0 \leq K \leq 300,000  All values in input are integers.         Input Input is given from Standard Input in the following format:  N  K  A_1  A_2  :  A_N       Output Print the answer.        Sample Input 1 10 3
1
5
4
3
8
6
9
7
2
4      Sample Output 1 7  For example, B = (1, 4, 3, 6, 9, 7, 4) satisfies the conditions.   It is a subsequence of A = (1, 5, 4, 3, 8, 6, 9, 7, 2, 4) .  All of the absolute differences between two adjacent elements ( |1-4|, |4-3|, |3-6|, |6-9|, |9-7|, |7-4| ) are at most K = 3 .

Solution (Python):

def segfunc(x, y):
    return max(x, y)



ide_ele = 0


class SegTree:
    """
    init(init_val, ide_ele): 配列init_valで初期化 O(N)
    update(k, x): k番目の値をxに更新 O(logN)
    query(l, r): 区間[l, r)をsegfuncしたものを返す O(logN)
    """
    def __init__(self, init_val, segfunc, ide_ele):
        """
        init_val: 配列の初期値
        segfunc: 区間にしたい操作
        ide_ele: 単位元
        n: 要素数
        num: n以上の最小の2のべき乗
        tree: セグメント木(1-index)
        """
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        """
        k番目の値をxに更新
        k: index(0-index)
        x: update value
        """
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        """
        [l, r)のsegfuncしたものを得る
        l: index(0-index)
        r: index(0-index)
        """
        res = self.ide_ele

        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res


a = input().split()
N = int(a[0])
M = int(a[1])
b = []
k = [int(input()) for i in range(N)]

temp = int(0)

for i in range(300001):
    b.append(0)
    
seg = SegTree(b, segfunc, ide_ele)

for i in range(N):
    temp = seg.query(max(0, k[i]-M), min(300001, k[i]+M+1))
    seg.update(k[i], temp+1)
    temp = 0
    
print(seg.query(0,300001))

Solution (Python):



def segfunc(x, y):
    return max(x, y)

ide_ele = 0

class SegTree:

    def __init__(self, init_val, segfunc, ide_ele):
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        res = self.ide_ele
        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res


N, K = map(int, input().split())


val = [0] * 300010
seg = SegTree(val, segfunc, ide_ele)
ans = 0

for i in range(N):
    a = int(input())
    
    
    l = max(a - K, 0)
    r = min(a + K, 300000)
    
    tmp = seg.query(l, r + 1) + 1
    ans = max(ans, tmp)
    seg.update(a, tmp)

print(ans)

Solution (Python):

def segfunc(x, y):
    return max(x, y)



ide_ele = 0


class SegTree:
    """
    init(init_val, ide_ele): 配列init_valで初期化 O(N)
    update(k, x): k番目の値をxに更新 O(logN)
    query(l, r): 区間[l, r)をsegfuncしたものを返す O(logN)
    """
    def __init__(self, init_val, segfunc, ide_ele):
        """
        init_val: 配列の初期値
        segfunc: 区間にしたい操作
        ide_ele: 単位元
        n: 要素数
        num: n以上の最小の2のべき乗
        tree: セグメント木(1-index)
        """
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        """
        k番目の値をxに更新
        k: index(0-index)
        x: update value
        """
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        """
        [l, r)のsegfuncしたものを得る
        l: index(0-index)
        r: index(0-index)
        """
        res = self.ide_ele

        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res


a = input().split()
N = int(a[0])
M = int(a[1])
b = []
k = [int(input()) for i in range(N)]

temp = int(0)

for i in range(300001):
    b.append(0)
    
seg = SegTree(b, segfunc, ide_ele)

for i in range(N):
    temp = seg.query(max(0, k[i]-M), min(300001, k[i]+M+1))
    seg.update(k[i], temp+1)
    temp = 0
    
print(seg.query(0,300001))

Solution (Python):
import sys

input = sys.stdin.readline

N, K = map(int, input().split())
A = []
for _ in range(N):
    A.append(int(input()))


import typing

def _ceil_pow2(n: int) -> int:
    x = 0
    while (1 << x) < n:
        x += 1

    return x


def _bsf(n: int) -> int:
    x = 0
    while n % 2 == 0:
        x += 1
        n //= 2

    return x

class SegTree:
    def __init__(self,
                 op: typing.Callable[[typing.Any, typing.Any], typing.Any],
                 e: typing.Any,
                 v: typing.Union[int, typing.List[typing.Any]]) -> None:
        self._op = op
        self._e = e

        if isinstance(v, int):
            v = [e] * v

        self._n = len(v)
        
        self._log = _ceil_pow2(self._n)
        self._size = 1 << self._log
        self._d = [e] * (2 * self._size)

        for i in range(self._n):
            self._d[self._size + i] = v[i]
        for i in range(self._size - 1, 0, -1):
            self._update(i)

    def set(self, p: int, x: typing.Any) -> None:
        assert 0 <= p < self._n

        p += self._size
        self._d[p] = x
        for i in range(1, self._log + 1):
            self._update(p >> i)

    def get(self, p: int) -> typing.Any:
        assert 0 <= p < self._n

        return self._d[p + self._size]

    def prod(self, left: int, right: int) -> typing.Any:
        assert 0 <= left <= right <= self._n
        sml = self._e
        smr = self._e
        left += self._size
        right += self._size

        while left < right:
            if left & 1:
                sml = self._op(sml, self._d[left])
                left += 1
            if right & 1:
                right -= 1
                smr = self._op(self._d[right], smr)
            left >>= 1
            right >>= 1

        return self._op(sml, smr)

    def all_prod(self) -> typing.Any:
        return self._d[1]

    def max_right(self, left: int,
                  f: typing.Callable[[typing.Any], bool]) -> int:
        assert 0 <= left <= self._n
        assert f(self._e)

        if left == self._n:
            return self._n

        left += self._size
        sm = self._e

        first = True
        while first or (left & -left) != left:
            first = False
            while left % 2 == 0:
                left >>= 1
            if not f(self._op(sm, self._d[left])):
                while left < self._size:
                    left *= 2
                    if f(self._op(sm, self._d[left])):
                        sm = self._op(sm, self._d[left])
                        left += 1
                return left - self._size
            sm = self._op(sm, self._d[left])
            left += 1

        return self._n

    def min_left(self, right: int,
                 f: typing.Callable[[typing.Any], bool]) -> int:
        assert 0 <= right <= self._n
        assert f(self._e)

        if right == 0:
            return 0

        right += self._size
        sm = self._e

        first = True
        while first or (right & -right) != right:
            first = False
            right -= 1
            while right > 1 and right % 2:
                right >>= 1
            if not f(self._op(self._d[right], sm)):
                while right < self._size:
                    right = 2 * right + 1
                    if f(self._op(self._d[right], sm)):
                        sm = self._op(self._d[right], sm)
                        right -= 1
                return right + 1 - self._size
            sm = self._op(self._d[right], sm)

        return 0

    def _update(self, k: int) -> None:
        self._d[k] = self._op(self._d[2 * k], self._d[2 * k + 1])



MAX_A = 3*10**5+5

dp = [0 for _ in range(MAX_A)]
segtree = SegTree(max, 0, [0] * MAX_A)
for i in range(N):
    x = A[i]
    l = max(0, x-K)
    r = min(MAX_A, x+K+1)
    now = segtree.prod(l, r) + 1
    segtree.set(x, now)

print(segtree.prod(0, MAX_A))

Solution (Python):



def segfunc(x, y):
    return max(x, y)

ide_ele = 0

class SegTree:

    def __init__(self, init_val, segfunc, ide_ele):
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        res = self.ide_ele
        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res



N, K = map(int, input().split())


val = [0] * 300010
seg = SegTree(val, segfunc, ide_ele)
ans = 0

for i in range(N):
    a = int(input())
    
    
    l = max(a - K, 0)
    r = min(a + K, 300000)
    
    tmp = seg.query(l, r + 1) + 1
    ans = max(ans, tmp)
    seg.update(a, tmp)

print(ans)

Solution (Python):


n,k = map(int,input().split())
a=[0 for i in range(n)]
for i in range(n):
    a[i] = int(input())
rank=[[] for i in range(n)]

ans = 1
for i in range(n):
    for r in range(ans,-1,-1):
        frag = 0
        for j in rank[r]:
            if abs(j-a[i])<=k:
                rank[r+1].append(a[i])
                ans = max(ans,r+2)
                frag =1
                break
        rank[0].append(a[i])
        if frag ==1:
            break


print(ans-1)

Solution (Python):
from typing import Callable, TypeVar, List

T = TypeVar('T')


class SegTree:
    def __init__(self, v: List[T], op: Callable[[T, T], T], e: Callable[[], T]) -> None:
        self.__dict__["_n"] = len(v)
        self.__dict__["log"] = (self.__dict__["_n"] - 1).bit_length()
        self.__dict__["size"] = 1 << self.log
        self.__dict__["d"] = [e() for _ in range(2 * self.size)]
        self.__dict__["op"] = op
        self.__dict__["e"] = e
        for i in range(self.__dict__["_n"]):
            self.__dict__["d"][self.size + i] = v[i]
        for i in reversed(range(1, self.__dict__["size"])):
            self.__update__(i)

    @classmethod
    def init_e(cls, n: int, op: Callable[[T, T], T], e: Callable[[], T]) -> 'SegTree':
        return cls([e() for _ in range(n)], op, e)

    def set(self, p: int, x: T) -> None:
        assert 0 <= p < self._n
        p += self.__dict__["size"]
        self.__dict__["d"][p] = x
        for i in range(1, self.log + 1):
            self.__update__(p >> i)

    def get(self, p: int) -> T:
        assert 0 <= p < self._n
        return self.__dict__["d"][p + self.__dict__["size"]]

    def prod(self, l: int, r: int) -> T:
        assert 0 <= l <= self._n and 0 <= r <= self._n
        sml = self.__dict__["e"]()
        smr = self.__dict__["e"]()
        l += self.__dict__["size"]
        r += self.__dict__["size"]

        while l < r:
            if l & 1:
                sml = self.__dict__["op"](sml, self.__dict__["d"][l])
                l += 1
            if r & 1:
                r -= 1
                smr = self.__dict__["op"](self.__dict__["d"][r], smr)
            l >>= 1
            r >>= 1
        return self.__dict__["op"](sml, smr)

    def all_prod(self) -> T:
        return self.__dict__["d"][1]

    def max_right(self, l: int, f: Callable[[T], bool]):
        assert 0 <= l <= self._n
        assert f(self.e())
        if l == self._n:
            return self._n
        l += self.size
        sm = self.e()
        while True:
            while l % 2 == 0:
                l >>= 1
            if not f(self.op(sm, self.d[l])):
                while l < self.size:
                    l *= 2
                    if f(self.op(sm, self.d[l])):
                        sm = self.op(sm, self.d[l])
                        l += 1
                return l - self.size
            sm = self.op(sm, self.d[l])
            l += 1
            if (l & -l) == l:
                return self._n

    def min_left(self, r: int, f: Callable[[T], bool]):
        assert 0 <= r <= self._n
        assert f(self.e())
        if r == 0:
            return 0
        r += self.size
        sm = self.e()
        while True:
            r -= 1
            while r > 1 and r % 2:
                r >>= 1
            if not f(self.op(self.d[r], sm)):
                while r < self.size:
                    r = 2 * r + 1
                    if f(self.op(self.d[r], sm)):
                        sm = self.op(self.d[r], sm)
                        r -= 1
                return r + 1 - self.size
            sm = self.op(self.d[r], sm)
            if (r & -r) == r:
                return 0

    def __update__(self, k: int) -> None:
        self.d[k] = self.op(self.d[2 * k], self.d[2 * k + 1])


n, k = map(int, input().split())
seg = SegTree([0]*400000, max, lambda: 0)
for _ in range(n):
    a = int(input())
    ma = seg.prod(max(0, a-k), min(400000, a+k+1))
    seg.set(a, ma+1)
print(seg.all_prod())

Solution (Python):



def segfunc(x, y):
    return max(x, y)

ide_ele = 0

class SegTree:

    def __init__(self, init_val, segfunc, ide_ele):
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        res = self.ide_ele
        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res



N, K = map(int, input().split())


val = [0] * 300000
seg = SegTree(val, segfunc, ide_ele)
ans = 0

for i in range(N):
    a = int(input())
    
    
    l = max(a - K, 0)
    r = min(a + K, 300000)
    tmp = seg.query(l, r + 1) + 1
    ans = max(ans, tmp)
    seg.update(a, tmp)

print(ans)

Solution (Python):






import sys
input = sys.stdin.readline
sys.setrecursionlimit(1000000)

import math

import bisect
import heapq
from collections import defaultdict
from collections import deque
from collections import Counter
from functools import lru_cache





MOD = 10**9+7
INF = float('inf')
AZ = "abcdefghijklmnopqrstuvwxyz"






def I(): return int(input().strip())
def S(): return input().strip()
def IL(): return list(map(int,input().split()))
def SL(): return list(map(str,input().split()))
def ILs(n): return list(int(input()) for _ in range(n))
def SLs(n): return list(input().strip() for _ in range(n))
def ILL(n): return [list(map(int, input().split())) for _ in range(n)]
def SLL(n): return [list(map(str, input().split())) for _ in range(n)]



def DD(arg): return defaultdict(arg)


def inv(n): return pow(n, MOD-2, MOD)


kaijo_memo = []
def kaijo(n):
  if(len(kaijo_memo) > n): return kaijo_memo[n]
  if(len(kaijo_memo) == 0): kaijo_memo.append(1)
  while(len(kaijo_memo) <= n): kaijo_memo.append(kaijo_memo[-1] * len(kaijo_memo) % MOD)
  return kaijo_memo[n]

gyaku_kaijo_memo = []
def gyaku_kaijo(n):
  if(len(gyaku_kaijo_memo) > n): return gyaku_kaijo_memo[n]
  if(len(gyaku_kaijo_memo) == 0): gyaku_kaijo_memo.append(1)
  while(len(gyaku_kaijo_memo) <= n): gyaku_kaijo_memo.append(gyaku_kaijo_memo[-1] * pow(len(gyaku_kaijo_memo),MOD-2,MOD) % MOD)
  return gyaku_kaijo_memo[n]

def nCr(n,r):
  if n == r: return 1
  if n < r or r < 0: return 0
  ret = 1
  ret = ret * kaijo(n) % MOD
  ret = ret * gyaku_kaijo(r) % MOD
  ret = ret * gyaku_kaijo(n-r) % MOD
  return ret


def factorization(n):
  arr = []
  temp = n
  for i in range(2, int(-(-n**0.5//1))+1):
    if temp%i==0:
      cnt=0
      while temp%i==0: 
        cnt+=1 
        temp //= i
      arr.append([i, cnt])
  if temp!=1: arr.append([temp, 1])
  if arr==[]: arr.append([n, 1])
  return arr


def make_divisors(n):
  divisors = []
  for i in range(1, int(n**0.5)+1):
    if n % i == 0:
      divisors.append(i)
      if i != n // i: 
        divisors.append(n//i)
  return divisors


def make_primes(N):
  max = int(math.sqrt(N))
  seachList = [i for i in range(2,N+1)]
  primeNum = []
  while seachList[0] <= max:
    primeNum.append(seachList[0])
    tmp = seachList[0]
    seachList = [i for i in seachList if i % tmp != 0]
  primeNum.extend(seachList)
  return primeNum


def gcd(a, b):
    while b: a, b = b, a % b
    return a


def lcm(a, b):
    return a * b // gcd (a, b)


def count_bit(n):
  count = 0
  while n:
    n &= n-1
    count += 1
  return count


def base_10_to_n(X, n):
  if X//n: return base_10_to_n(X//n, n)+[X%n]
  return [X%n]

def base_n_to_10(X, n):
  return sum(int(str(X)[-i-1])*n**i for i in range(len(str(X))))

def base_10_to_n_without_0(X, n):
  X -= 1
  if X//n: return base_10_to_n_without_0(X//n, n)+[X%n]
  return [X%n]


def int_log(n, a):
  count = 0
  while n>=a:
    n //= a
    count += 1
  return count





N,K = IL()
A = ILs(N)

class SegmentTree:
  def __init__(self, n, op, e):
    self.n = n
    self.op = op
    self.e = e
    self.size = 2 ** ((n - 1).bit_length())
    self.node = [self.e] * (2 * self.size)
 
  def build(self, array):
    for i in range(self.n):
      self.node[self.size + i] = array[i]
    for i in range(self.size - 1, 0, -1):
      self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1])
 
  def update(self, i, val):
    i += self.size
    self.node[i] = val
    while i > 1:
      i >>= 1
      self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1])
 
  def get(self, l, r):
    l, r = l + self.size, r + self.size
    res_l, res_r = self.e, self.e
    while l < r:
      if l & 1:
        res_l = self.op(res_l, self.node[l])
        l += 1
      if r & 1:
        r -= 1
        res_r = self.op(self.node[r], res_r) 
      l, r = l >> 1, r >> 1
    return self.op(res_l, res_r)
  
ST = SegmentTree(330000,max,0)

for a in A:
  a += 1
  l = max(1,a-K)
  r = min(310000,a+K)
  ST.update(a,ST.get(l,r+1)+1)
print(ST.get(1,310000))

Solution (Python):
class Segment_Tree():
    """
    このプログラム内は1-index
    """

    def __init__(self,L,calc,unit):
        """calcを演算とするリストLのSegment Treeを作成

        calc:演算(2変数関数,モノイド)
        unit:モノイドcalcの単位元 (xe=ex=xを満たすe)
        """
        self.calc=calc
        self.unit=unit

        N=len(L)
        d=max(1,(N-1).bit_length())
        k=1<<d

        self.data=[unit]*k+L+[unit]*(k-len(L))
        self.N=k
        self.depth=d

        for i in range(k-1,0,-1):
            self.data[i]=calc(self.data[i<<1],self.data[i<<1|1])

    def get(self,k,index=1):
        """第k要素を取得
        """
        assert 0<=k-index<self.N,"添字が範囲外"
        return self.data[k-index+self.N]

    def update(self,k,x,index=1):
        """第k要素をxに変え,更新を行う.

        k:数列の要素
        x:更新後の値
        """
        assert 0<=k-index<self.N,"添字が範囲外"
        m=(k-index)+self.N
        self.data[m]=x

        while m>1:
            m>>=1
            self.data[m]=self.calc(self.data[m<<1],self.data[m<<1|1])


    def product(self,From,To,index=1,left_closed=True,right_closed=True):
        L=(From-index)+self.N+(not left_closed)
        R=(To-index)+self.N+(right_closed)

        vL=self.unit
        vR=self.unit

        while L<R:
            if L&1:
                vL=self.calc(vL,self.data[L])
                L+=1

            if R&1:
                R-=1
                vR=self.calc(self.data[R],vR)

            L>>=1
            R>>=1

        return self.calc(vL,vR)

    def all_prod(self):
        return self.data[1]

N,K=map(int,input().split())
A=[0]*N
for i in range(N):
    A[i]=int(input())

T=max(A)
S=Segment_Tree([0]*(T+1),max,0)
DP=[0]*N

for i in range(N-1,-1,-1):
    X=S.product(max(0,A[i]-K),min(T,A[i]+K),0)
    DP[i]=X+1
    S.update(A[i],X+1,0)

print(max(DP))

Solution (Python):
class SegmentTree: 
    def __init__(self,list,f=lambda x,y:x+y,inf=0):
        self.height=(len(list)-1).bit_length()+1 
        self.zero=2**(self.height-1) 
        self.id=inf 
        self.tree=[self.id]*(2**self.height) 
        self.f=f
        for i in range(len(list)):
            self.tree[self.zero+i]=list[i]
        for i in range(self.zero-1,0,-1):
            self.tree[i]=self.f(self.tree[2*i],self.tree[2*i+1])
        
    def update(self,i,x): 
        i+=self.zero
        self.tree[i]=x
        while i>1:
            i//=2
            self.tree[i]=self.f(self.tree[2*i],self.tree[2*i+1])
    
    def query(self,l,r): 
        l+=self.zero
        r+=self.zero
        lf,rf=self.id,self.id
        while l<r:
            if l&1:
                lf=self.f(lf,self.tree[l])
                l+=1
            if r&1:
                r-=1
                rf=self.f(self.tree[r],rf)
            l//=2
            r//=2
        return self.f(lf,rf)

    '''
    FFFFTTTTとしたときの最小のTを求める
    '''
    def BinarySearch(self,l,r,f): 
        if not f(self.query(l,r)): 
            return r
        l+=self.zero
        while True:
            if f(self.tree[l]):
                if l>=self.zero:
                    return l-self.zero+1 
                else:
                    l*=2 
            else:
                if l%2==0:
                    l+=1 
                else:
                    l=(l//2)+1 

n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]
am=300005
S=SegmentTree([0]*am,max)
for i in range(n):
    x=S.query(max(0,a[i]-k),min(a[i]+k+1,am))
    S.update(a[i],x+1)
print(S.query(0,am))

Solution (Python):
class SegmentTree:
    def __init__(self, lis, ele, op):
        self.len = len(lis)
        self.n = 1 << ((self.len - 1).bit_length())
        self.op = op
        self.ele = ele
        self.tree = self._build(lis)
    def _build(self, lis):
        res_tree = [self.ele] * (self.n - 1) + lis + [self.ele] * (self.n - self.len)
        for i in range(self.n - 2, -1, -1):
            res_tree[i] = self.op(res_tree[i * 2 + 1], res_tree[i * 2 + 2])
        return res_tree
    def __get__(self, i):
        return self.tree[self.n + i - 1]
    def update(self, i, x):
        i += self.n - 1
        self.tree[i] = x
        while i > 0:
            i -= 1
            i >>= 1
            self.tree[i] = self.op(self.tree[i * 2 + 1], self.tree[i * 2 + 2])
    def query(self, l, r):
        l +=  self.n - 1
        r += self.n - 1
        L = self.ele
        R = self.ele
        while l < r:
            if l & 1 == 0:
                L = self.op(L, self.tree[l])
                l += 1
            if r & 1 == 0:
                r -= 1
                R = self.op(R, self.tree[r])
            l -= 1
            l >>= 1
            r >>= 1
        return self.op(L, R)
n, k = map(int, input().split())
ST = SegmentTree([0] * 600000, 0, max)
for i in range(n):
    a = int(input())
    res = ST.query(max(0, a - k), min(600000, a + k + 1))
    ST.update(a, res + 1)
print(ST.tree[1])

Solution (Python):
from typing import Callable, TypeVar, List

T = TypeVar('T')


class SegTree:
    __slots__ = ["_n", "log", "size", "d", "op", "e"]
    def __init__(self, v: List[T], op: Callable[[T, T], T], e: Callable[[], T]) -> None:
        self._n = len(v)
        self.log = (self._n - 1).bit_length()
        self.size = 1 << self.log
        self.d = [e() for _ in range(2 * self.size)]
        self.op = op
        self.e = e
        for i in range(self._n):
            self.d[self.size + i] = v[i]
        for i in reversed(range(1, self.size)):
            self.__update__(i)

    @classmethod
    def init_e(cls, n: int, op: Callable[[T, T], T], e: Callable[[], T]) -> 'SegTree':
        return cls([e() for _ in range(n)], op, e)

    def set(self, p: int, x: T) -> None:
        assert 0 <= p < self._n
        p += self.size
        self.d[p] = x
        for i in range(1, self.log + 1):
            self.__update__(p >> i)

    def get(self, p: int) -> T:
        assert 0 <= p < self._n
        return self.d[p + self.size]

    def prod(self, l: int, r: int) -> T:
        assert 0 <= l <= self._n and 0 <= r <= self._n
        sml = self.e()
        smr = self.e()
        l += self.size
        r += self.size

        while l < r:
            if l & 1:
                sml = self.op(sml, self.d[l])
                l += 1
            if r & 1:
                r -= 1
                smr = self.op(self.d[r], smr)
            l >>= 1
            r >>= 1
        return self.op(sml, smr)

    def all_prod(self) -> T:
        return self.d[1]

    def max_right(self, l: int, f: Callable[[T], bool]):
        assert 0 <= l <= self._n
        assert f(self.e())
        if l == self._n:
            return self._n
        l += self.size
        sm = self.e()
        while True:
            while l % 2 == 0:
                l >>= 1
            if not f(self.op(sm, self.d[l])):
                while l < self.size:
                    l *= 2
                    if f(self.op(sm, self.d[l])):
                        sm = self.op(sm, self.d[l])
                        l += 1
                return l - self.size
            sm = self.op(sm, self.d[l])
            l += 1
            if (l & -l) == l:
                return self._n

    def min_left(self, r: int, f: Callable[[T], bool]):
        assert 0 <= r <= self._n
        assert f(self.e())
        if r == 0:
            return 0
        r += self.size
        sm = self.e()
        while True:
            r -= 1
            while r > 1 and r % 2:
                r >>= 1
            if not f(self.op(self.d[r], sm)):
                while r < self.size:
                    r = 2 * r + 1
                    if f(self.op(self.d[r], sm)):
                        sm = self.op(self.d[r], sm)
                        r -= 1
                return r + 1 - self.size
            sm = self.op(self.d[r], sm)
            if (r & -r) == r:
                return 0

    def __update__(self, k: int) -> None:
        self.d[k] = self.op(self.d[2 * k], self.d[2 * k + 1])


n, k = map(int, input().split())
seg = SegTree([0]*400000, max, lambda: 0)
for _ in range(n):
    a = int(input())
    ma = seg.prod(max(0, a-k), min(400000, a+k+1))
    seg.set(a, ma+1)
print(seg.all_prod())