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):
import typing
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]]):
        self._op = op
        self._e = e

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

        self._n = len(v)
        self._log = self._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 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 _update(self, k: int) -> None:
        self._d[k] = self._op(self._d[2 * k], self._d[2 * k + 1])
    
    def _ceil_pow2(self, n: int) -> int:
        x = 0
        while (1 << x) < n:
            x += 1
        return x

N, K = map(int, input().split())
A = list(int(input()) for _ in range(N))
max_A = max(A)
seg = SegTree(max, -1, [0]*(max_A+1))
for v in A:
    l = max(0, v-K)
    r = min(max_A, v+K)
    seg.set(v, seg.prod(l, r+1)+1)
print(seg.all_prod())

Solution (Python):
import typing
class SegTree:
    def _ceil_pow2(self, n: int) -> int:
        x = 0
        while (1 << x) < n:
            x += 1
        return x
    
    def __init__(self,
                 op: typing.Callable[[typing.Any, typing.Any], typing.Any],
                 e: typing.Any,
                 v: typing.Union[int, typing.List[typing.Any]]):
        self._op = op
        self._e = e

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

        self._n = len(v)
        self._log = self._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 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 _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())
A = list(int(input()) for _ in range(N))
max_A = max(A)
seg = SegTree(max, -1, [0]*(max_A+1))
for v in A:
    l = max(0, v-K)
    r = min(max_A, v+K)
    seg.set(v, seg.prod(l, r+1)+1)
print(seg.all_prod())

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

"""使用例"""

n,k=map(int,input().split())
A=[int(input()) for i in range(n)]

T=[0 for i in range(300000+1)]
T=SegTree(T,segfunc,ide_ele)

for num in A:
    now=T.query(max(0,num-k),min(num+k+1,300002))
    
    T.update(num,now+1)

print(T.query(0,300001))

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

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

def init(init_val):
  for i in range(n):
    seg[i+num-1]=init_val[i]
  for i in range(num-2,-1,-1):
    seg[i]=segfunc(seg[2*i+1],seg[2*i+2])

def update(k,x):
  k+=num-1
  seg[k]=x
  while k:
    k=(k-1)//2
    seg[k]=segfunc(seg[k*2+1],seg[k*2+2])

def query(p,q):
  if q<=p:
    return ide_ele
  p+=num-1
  q+=num-2
  res=ide_ele
  while q-p>1:
    if p&1==0:
      res=segfunc(res,seg[p])
    if q&1==1:
      res=segfunc(res,seg[q])
      q-=1
    p=p//2
    q=(q-1)//2
  if p==q:
    res=segfunc(res,seg[p])
  else:
    res=segfunc(segfunc(res,seg[p]),seg[q])
  return res

ide_ele=0

num=3*10**5+1
seg=[ide_ele]*2*num

dp=[0]*(max(a)+1)
dp[a[0]]=1
update(a[0],1)
for i in range(1,n):
  dp[a[i]]=query(max(a[i]-k,0),min(a[i]+k+1,3*10**5+1))+1
  update(a[i],dp[a[i]])
print(max(dp))

Solution (Python):


import sys
import math
from bisect import bisect_right as br
from bisect import bisect_left as bl
sys.setrecursionlimit(2147483647)
from heapq import heappush, heappop,heappushpop
from collections import defaultdict
from itertools import accumulate
from collections import Counter
from collections import deque
from operator import itemgetter
from itertools import permutations
mod = 10**9 + 7
inf = float('inf')
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))




n, k = LI()
a = [I() for _ in range(n)]

def init_max(init_max_val):
    
    for i in range(num_max-2,-1,-1) :
        seg_max[i]=max(seg_max[2*i+1],seg_max[2*i+2]) 
    
def update_max(k,x):
    k += num_max-1
    seg_max[k] = x
    while k:
        k = (k-1)//2
        seg_max[k] = max(seg_max[k*2+1],seg_max[k*2+2])
    
def query_max(p,q):
    if q<=p:
        return ide_ele_max
    p += num_max-1
    q += num_max-2
    res=ide_ele_max
    while q-p>1:
        if p&1 == 0:
            res = max(res,seg_max[p])
        if q&1 == 1:
            res = max(res,seg_max[q])
            q -= 1
        p = p//2
        q = (q-1)//2
    if p == q:
        res = max(res,seg_max[p])
    else:
        res = max(max(res,seg_max[p]),seg_max[q])
    return res


ide_ele_max = 0
ma = max(a)

num_max =2**(ma-1).bit_length()
seg_max=[ide_ele_max]*2*num_max
init_max(a)
for ai in a:
    res = query_max(max(0, ai-k), min(ai+k+1, num_max))
    update_max(ai, res+1)
print(max(seg_max))

Solution (Python):
import typing
def _ceil_pow2(n: int) -> int:
    x = 0
    while (1 << x) < n:
        x += 1
    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]]):
        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])

N, K = map(int, input().split())
A = list(int(input()) for _ in range(N))
max_A = max(A)
seg = SegTree(max, 0, [0]*(max_A+1))
for v in A:
    l = max(0, v-K)
    r = min(max_A, v+K)
    seg.set(v, seg.prod(l, r+1)+1)
print(seg.all_prod())

Solution (Python):

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



ide_ele = int(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(N)
    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

n, k = map(int, input().split())
a = [0]*300002

seg = SegTree(a, segfunc, ide_ele)
for _ in range(n):
    aa = int(input())

    m = seg.query(max(0,aa-k), min(aa+k,300000)+1)
    seg.update(aa, m+1)

print(seg.query(0, 300000))

Solution (Python):
from math import ceil, log2
import sys
z=sys.stdin.readline



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




ide_ele = -1



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, z().split())
a = [int(z()) for _ in range(n)]
M=300001
st = SegTree([0]*M, max, 0)
res = 0
for i in a:
    min_a = max(i-k, 0)
    max_a = min(i+k, M)
    s = st.query(min_a, max_a+1)
    st.update(i, max(s, 0)+1)
    res = max(res, max(s, 0) + 1)

print(res)

Solution (Python):
n, k = map(int, input().split())
a_list = [int(input()) for _ in range(n)]

dp = [1] * n

for i in range(n):
    for j in range(max(0, i - 100), i):
        if abs(a_list[i] - a_list[j]) <= k:
            dp[i] = max(dp[i], dp[j] + 1)

ans = max(dp)
print(ans)

Solution (Python):
import os
import sys
from io import BytesIO, IOBase

class SegmentTree:
    def __init__(self, data, default=0, func=max):
        """initialize the segment tree with data"""
        self._default = default
        self._func = func
        self._len = len(data)
        self._size = _size = 1 << (self._len - 1).bit_length()

        self.data = [default] * (2 * _size)
        self.data[_size:_size + self._len] = data
        for i in reversed(range(_size)):
            self.data[i] = func(self.data[i + i], self.data[i + i + 1])

    def __delitem__(self, idx):
        self[idx] = self._default

    def __getitem__(self, idx):
        return self.data[idx + self._size]

    def __setitem__(self, idx, value):
        idx += self._size
        self.data[idx] = value
        idx >>= 1
        while idx:
            self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
            idx >>= 1

    def __len__(self):
        return self._len

    def query(self, start, stop):
        """func of data[start, stop)"""
        start += self._size
        stop += self._size

        res_left = res_right = self._default
        while start < stop:
            if start & 1:
                res_left = self._func(res_left, self.data[start])
                start += 1
            if stop & 1:
                stop -= 1
                res_right = self._func(self.data[stop], res_right)
            start >>= 1
            stop >>= 1

        return self._func(res_left, res_right)

    def __repr__(self):
        return "SegmentTree({0})".format(self.data)

def main():
    mxn = int(3e5) + 1
    _, k, *a = map(int, open(0).read().split())
    st = SegmentTree([0] * mxn)
    for i in a:
        q = st.query(max(i - k, 0), min(mxn, i + k + 1))
        st[i] = q + 1
    print(st.query(0, mxn))





BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)


def input(): return sys.stdin.readline().rstrip("\r\n")
def getint(): return int(input())
def getints(): return list(map(int, input().split()))
def getint1(): return list(map(lambda x: int(x) - 1, input().split()))





if __name__ == "__main__":
    main()

Solution (Python):
import os
import sys
from io import BytesIO, IOBase

class SegmentTree:
    def __init__(self, data, default=0, func=max):
        """initialize the segment tree with data"""
        self._default = default
        self._func = func
        self._len = len(data)
        self._size = _size = 1 << (self._len - 1).bit_length()

        self.data = [default] * (2 * _size)
        self.data[_size:_size + self._len] = data
        for i in reversed(range(_size)):
            self.data[i] = func(self.data[i + i], self.data[i + i + 1])

    def __delitem__(self, idx):
        self[idx] = self._default

    def __getitem__(self, idx):
        return self.data[idx + self._size]

    def __setitem__(self, idx, value):
        idx += self._size
        self.data[idx] = value
        idx >>= 1
        while idx:
            self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
            idx >>= 1

    def __len__(self):
        return self._len

    def query(self, start, stop):
        """func of data[start, stop)"""
        start += self._size
        stop += self._size

        res_left = res_right = self._default
        while start < stop:
            if start & 1:
                res_left = self._func(res_left, self.data[start])
                start += 1
            if stop & 1:
                stop -= 1
                res_right = self._func(self.data[stop], res_right)
            start >>= 1
            stop >>= 1

        return self._func(res_left, res_right)

    def __repr__(self):
        return "SegmentTree({0})".format(self.data)

def main():
    mxn = int(3e5) + 1
    n, k = getints()
    st = SegmentTree([0] * mxn)
    for _ in range(n):
        i = getint()
        q = st.query(max(i - k, 0), min(mxn, i + k + 1))
        st[i] = q + 1
    print(st.query(0, mxn))





BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)


def input(): return sys.stdin.readline().rstrip("\r\n")
def getint(): return int(input())
def getints(): return list(map(int, input().split()))
def getint1(): return list(map(lambda x: int(x) - 1, input().split()))





if __name__ == "__main__":
    main()

Solution (Python):
class SegmentTree():
    """
    update, get を提供するSegmentTree

    Attributes
    ----------
    __n : int
        葉の数。2 ^ i - 1
    __dot :
        Segment function
    __e: int
        単位元
    __node: list
        Segment Tree
    """
    def __init__(self, A, dot, e):
        """
        Parameters
        ----------
        A : list
            対象の配列
        dot :
            Segment function
        e : int
            単位元
        """
        n = 2 ** (len(A) - 1).bit_length()
        self.__n = n
        self.__dot = dot
        self.__e = e
        self.__node = [e] * (2 * n)
        for i in range(len(A)):
            self.__node[i + n] = A[i]
        for i in range(n - 1, 0, -1):
            self.__node[i] = self.__dot(self.__node[2 * i], self.__node[2 * i + 1])
    
    def update(self, i, c):
        i += self.__n
        node = self.__node
        node[i] = c
        while i > 1:
            i //= 2
            node[i] = self.__dot(node[2 * i], node[2 * i + 1])

    def get(self, l, r):
        vl, vr = self.__e, self.__e
        l += self.__n
        r += self.__n
        while (l < r):
            if l & 1:
                vl = self.__dot(vl, self.__node[l])
                l += 1
            l //= 2
            if r & 1:
                r -= 1
                vr = self.__dot(vr, self.__node[r])
            r //= 2
        return self.__dot(vl, vr)


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

st = SegmentTree([N] * (max_A + 1), min, N)
dp = [0] * (N + 1)
for i, a in enumerate(reversed(A)):
    j = N - 1 - i
    p1 = st.get(a, min(max_A + 1, a + K + 1))
    dp[j] = max(dp[p1] + 1, dp[j])
    p2 = st.get(max(0, a - K), a)
    dp[j] = max(dp[p2] + 1, dp[j])
    st.update(a, j)

print(max(dp))

Solution (Python):
class SegmentTree():
    """
    update, get を提供するSegmentTree

    Attributes
    ----------
    __n : int
        葉の数。2 ^ i - 1
    __dot :
        Segment function
    __e: int
        単位元
    __node: list
        Segment Tree
    """
    def __init__(self, A, dot, e):
        """
        Parameters
        ----------
        A : list
            対象の配列
        dot :
            Segment function
        e : int
            単位元
        """
        n = 2 ** (len(A) - 1).bit_length()
        self.__n = n
        self.__dot = dot
        self.__e = e
        self.__node = [e] * (2 * n)
        for i in range(len(A)):
            self.__node[i + n] = A[i]
        for i in range(n - 1, 0, -1):
            self.__node[i] = self.__dot(self.__node[2 * i], self.__node[2 * i + 1])
    
    def update(self, i, c):
        i += self.__n
        node = self.__node
        node[i] = c
        while i > 1:
            i //= 2
            node[i] = self.__dot(node[2 * i], node[2 * i + 1])

    def get(self, l, r):
        vl, vr = self.__e, self.__e
        l += self.__n
        r += self.__n
        while (l < r):
            if l & 1:
                vl = self.__dot(vl, self.__node[l])
                l += 1
            l //= 2
            if r & 1:
                r -= 1
                vr = self.__dot(vr, self.__node[r])
            r //= 2
        return self.__dot(vl, vr)


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

st = SegmentTree([N] * (max_A + 1), min, N)
dp = [1] * N
for i, a in enumerate(reversed(A)):
    j = N - 1 - i
    p1 = st.get(a, min(max_A + 1, a + K + 1))
    if p1 < N:
        dp[j] = max(dp[p1] + 1, dp[j])
    p2 = st.get(max(0, a - K), a)
    if p2 < N:
        dp[j] = max(dp[p2] + 1, dp[j])
    st.update(a, j)

print(max(dp))

Solution (Python):




import sys

def read_str(): return sys.stdin.readline().strip()
def read_int(): return int(sys.stdin.readline().strip())
def read_ints(): return map(int, sys.stdin.readline().strip().split())
def read_str_split(): return list(sys.stdin.readline().strip())
def read_int_list(): return list(map(int, sys.stdin.readline().strip().split()))

class segtree:
    def __init__(self, op, e, v: list):
        self._n = len(v)
        self.log = ceil_pow2(self._n)
        self.size = 1 << self.log
        self.op = op; self.e = e
        self.d = [self.e()] * (self.size * 2)
        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: int):
        assert 0 <= p and 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):
        assert 0 <= p and p < self._n
        return self.d[p + self.size]

    def prod(self, l: int, r: int):
        assert 0 <= l and l <= r and r <= self._n
        l += self.size; r += self.size
        sml, smr = self.e(), self.e()
        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): return self.d[1]

    def max_right(self, l: int, f):
        assert 0 <= l and 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 * l
                    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: break
        return self._n

    def min_left(self, r: int, f):
        assert 0 <= r and 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: break
        return 0

    def __update(self, k: int): self.d[k] = self.op(self.d[k * 2], self.d[k * 2 + 1])

def ceil_pow2(n: int) -> int:
    x = 0
    while (1 << x) < n: x += 1
    return x

def op(a, b): return max(a, b)
def e(): return 0

def Main():
    n, k = read_ints()
    A = [read_int() for _ in range(n)]
    seg = segtree(op, e, [0] * 300005)
    seg.set_(A[0], 1)
    for i in range(1, n):
        seg.set_(A[i], seg.prod(max(A[i] - k, 0), min(A[i] + k + 1, 300005)) + 1)
    print(seg.prod(0, 300005))

if __name__ == '__main__':
    Main()