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 in Rust (1.42.0) (judge verdict: Wrong Answer)

#![allow(unused_parens)]
#![allow(unused_imports)]
#![allow(non_upper_case_globals)]
#![allow(non_snake_case)]
#![allow(unused_mut)]
#![allow(unused_variables)]
#![allow(dead_code)]

use itertools::Itertools;
use proconio::input;
use proconio::marker::{Chars, Usize1};

#[allow(unused_macros)]
#[cfg(debug_assertions)]
macro_rules! mydbg {
    //($arg:expr) => (dbg!($arg))
    //($arg:expr) => (println!("{:?}",$arg));
      ($($a:expr),*) => {
          eprintln!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
      }
}
#[cfg(not(debug_assertions))]
macro_rules! mydbg {
    ($($arg:expr),*) => {};
}

macro_rules! echo {
    ($($a:expr),*) => {
          $(println!("{}",$a))*
      }
}

use std::cmp::*;
use std::collections::*;
use std::ops::{Add, Div, Mul, Sub};

#[allow(dead_code)]
static INF_I64: i64 = 92233720368547758;
#[allow(dead_code)]
static INF_I32: i32 = 21474836;
#[allow(dead_code)]
static INF_USIZE: usize = 18446744073709551;
#[allow(dead_code)]
static M_O_D: usize = 1000000007;
#[allow(dead_code)]
static PAI: f64 = 3.1415926535897932;

trait IteratorExt: Iterator {
    fn toVec(self) -> Vec<Self::Item>;
}

impl<T: Iterator> IteratorExt for T {
    fn toVec(self) -> Vec<Self::Item> {
        self.collect()
    }
}

trait CharExt {
    fn toNum(&self) -> usize;
    fn toAlphabetIndex(&self) -> usize;
    fn toNumIndex(&self) -> usize;
}
impl CharExt for char {
    fn toNum(&self) -> usize {
        return *self as usize;
    }
    fn toAlphabetIndex(&self) -> usize {
        return self.toNum() - 'a' as usize;
    }
    fn toNumIndex(&self) -> usize {
        return self.toNum() - '0' as usize;
    }
}

trait VectorExt {
    fn joinToString(&self, s: &str) -> String;
}
impl<T: ToString> VectorExt for Vec<T> {
    fn joinToString(&self, s: &str) -> String {
        return self
            .iter()
            .map(|x| x.to_string())
            .collect::<Vec<_>>()
            .join(s);
    }
}

trait StringExt {
    fn get_reverse(&self) -> String;
}
impl StringExt for String {
    fn get_reverse(&self) -> String {
        self.chars().rev().collect::<String>()
    }
}

trait UsizeExt {
    fn pow(&self, n: usize) -> usize;
}
impl UsizeExt for usize {
    fn pow(&self, n: usize) -> usize {
        return ((*self as u64).pow(n as u32)) as usize;
    }
}

pub trait Monoid {
    type T: Clone;
    fn id() -> Self::T;
    fn op(a: &Self::T, b: &Self::T) -> Self::T;
}
pub struct SegTree<M: Monoid> {
    n: usize,
    data: Vec<M::T>,
}
impl<M: Monoid> SegTree<M> {
    pub fn new(n_: usize) -> SegTree<M> {
        let mut n = 1 as usize;
        while (n < n_) {
            n *= 2;
        }
        SegTree {
            n: n,
            data: vec![M::id().clone(); (2 * n)],
        }
    }
    #[macro_use]
    pub fn update(&mut self, index: usize, v: M::T) {
        let mut k = index + self.n - 1;
        self.data[k] = v;
        while (k > 0) {
            k = (k - 1) / 2;
            self.data[k] = M::op(&self.data[2 * k + 1], &self.data[2 * k + 2]);
        }
    }
    pub fn query(&mut self, l: usize, r: usize) -> M::T {
        let mut l = l + self.n - 1;
        let mut r = r + self.n - 1;
        if (l == r) {
            return M::op(&M::id().clone(), &self.data[l]);
        }
        mydbg!((self.n, (&self.data.len() + 1) / 2));
        let mut ret = M::id().clone();
        while (l < r) {
            if (l % 2 == 0) {
                ret = M::op(&ret, &self.data[l]);
                mydbg!(("left", l, r));
            }
            if (r % 2 == 0) {
                ret = M::op(&ret, &self.data[r - 1]);
                mydbg!(("right", l, r));
            }
            l = l / 2;
            r = (r - 1) / 2;
        }
        return ret;
    }
}
struct MAX;
impl Monoid for MAX {
    type T = u64;
    fn id() -> Self::T {
        0
    }
    fn op(a: &Self::T, b: &Self::T) -> Self::T {
        max(*a, *b)
    }
}

fn main() {
    input! {
       N: usize,
       K:i64,
       A:[i64;N],
    }

    let mut ans: usize = 0;
    let mut dp = vec![0; N + 5];
    let mut tmp: SegTree<MAX> = SegTree::new(3 * 100005);

    for i in 0..N {
        let a = A[i];
        let b = tmp.query(a as usize, min(a + K + 1, 3 * 100005) as usize);
        let c = tmp.query(max(a - K, 0) as usize, (a + 1) as usize);
        dp[i + 1] = max(c, b) + 1;
        tmp.update(a as usize, dp[i + 1]);
    }

    echo!(dp[N]);
}