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 C++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll ash[100001];
ll f(ll a[],ll k,ll n,ll pp,ll start)
{
    //cout<<a[pp]<<" ";
    if(start==n)
    {
    return 1;
    }
    if(ash[start]!=-1)
    return ash[start];
    if(abs(a[pp]-a[start])<=k)
    return  ash[start]= 1+f(a,k,n,start,start+1);
   else
   return ash[start]=max(f(a,k,n,pp,start+1),f(a,k,n,start,start+1));
    
    
}
int main()
{
    memset(ash,-1,sizeof(ash));
ll n,k;
cin>>n>>k;
ll a[n];
for(int i=0;i<n;i++)
cin>>a[i];
cout<<f(a,k,n,0,1);
}