Buggy python submission (verdict: Runtime Error):

## https://atcoder.jp/contests/abc170/submissions/14416787

import sys
input=sys.stdin.readline

class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(300001)]

st=SegmentTree(300001,0)

for ai in a:
    l=max(0,ai-k)
    r=min(n+1,ai+k+1)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,n+1))
  

Fixed submission:

## https://atcoder.jp/contests/abc170/submissions/14416787
class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]

st=SegmentTree(300001,0)
##queryが開区間でない
for ai in a:
    l=max(0,ai-k)
    r=min(300001,ai+k)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,300001))

Buggy python submission (verdict: Runtime Error):
## https://atcoder.jp/contests/abc170/submissions/14416787

import sys
input=sys.stdin.readline

class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]

st=SegmentTree(n+2,0)

for ai in a:
    l=max(0,ai-k)
    r=min(n+1,ai+k+1)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,n+1))
  

Fixed submission:

## https://atcoder.jp/contests/abc170/submissions/14416787
class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]

st=SegmentTree(300001,0)
##queryが開区間でない
for ai in a:
    l=max(0,ai-k)
    r=min(300001,ai+k)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,300001))

Buggy python submission (verdict: Runtime Error):

## https://atcoder.jp/contests/abc170/submissions/14416787
import heapq
import sys
input=sys.stdin.readline

class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]

st=SegmentTree(n+1,0)

for ai in a:
    l=max(0,ai-k)
    r=min(n+1,ai+k+1)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,n+1))
  

Fixed submission:

## https://atcoder.jp/contests/abc170/submissions/14416787
class SegmentTree():
    def __init__(self,n,init):
        self.offset=2**((n-1).bit_length())
        self.tree=[init]*(2*self.offset)
        self.init=init
    def update(self,pos,val):
        pos+=self.offset
        self.tree[pos]=val
        while pos>1:
            pos=pos//2
            self.tree[pos]=max(self.tree[2*pos],self.tree[2*pos+1])
    def query(self,l,r):
        l+=self.offset
        r+=self.offset
        ret=self.init
        while l<=r:
            ret=max(ret,self.tree[r])
            r=(r-1)//2
            ret=max(ret,self.tree[l])
            l=(l+1)//2
        return ret

import sys
input=sys.stdin.readline
n,k=map(int,input().split())
a=[int(input()) for _ in range(n)]

st=SegmentTree(300001,0)
##queryが開区間でない
for ai in a:
    l=max(0,ai-k)
    r=min(300001,ai+k)
    m=st.query(l,r)
    st.update(ai,m+1)

print(st.query(0,300001))