/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		int n = 6;
		int k = 2;
		int M = 2;
 
		int[] arr = {1, 2, 3, 10, 11, 12};
 
		int[] dp = new int[n + 1];
		Arrays.fill(dp, 100);
 
		for(int i = 0; i < k - 1; i++) dp[i] = 0;
 
		for(int i = 0; i < n; i++){
 
			int low = arr[i];
			int high = arr[i];
			int j = i - k;
			int ans = 100;
 
			while(j >= 0 && high - low <= M){
			ans = Math.min(ans, 1 + dp[j]);	
			low = Math.min(low, arr[j]);
			high = Math.max(high, arr[j]);
			j--;
			}
			dp[i+1] = ans;
		}
 
		System.out.println(dp[n]);
	}
}

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