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<stdio.h>
#include<stdlib.h>

int main(void){
    long int n,k;
    scanf("%ld %ld",&n,&k);
    long int a[n-1];
    for(long int i=1; i<=n; i++) scanf("%ld",&a[i-1]);

    long int kiroku,koma,ans;
    ans = 1;

    for(long int i=1; i<n; i++){
        kiroku = 1;
        koma   = a[i-1];
        for(long int j=i; j<=n; j++){
            if(labs(a[j-1]-a[j]) <= k){
                kiroku += 1;
                koma   =  a[j]; 
            }else{
                koma = a[j+1];
            }
        }
        if(kiroku > ans)    ans = kiroku;
    }

    printf("%ld",ans);
    return 0;
}