Longest Subarray with K Distinct Integers

You are given an array A of n integers and an integer k. Your task is to find the length of the longest contiguous subarray that contains at most k distinct integers. In other words, if we denote by \(D(x)\) the number of distinct integers in subarray x, you need to find the maximum length \(L\) such that there exists a subarray with L elements and \(D(x) \le k\).

Example: For A = [1, 2, 1, 2, 3, 4, 1] and k = 2, the longest subarray with at most 2 distinct integers is [1, 2, 1, 2], which has a length of 4.

This problem can be efficiently solved using the sliding window technique.

inputFormat

The first line contains two integers n and k (the size of the array and the maximum number of distinct integers allowed, respectively). The second line contains n integers representing the array A.

Constraints:

• 1 ≤ n ≤ 10⁵
• 0 ≤ k ≤ n
• The elements of A are integers.

outputFormat

Output a single integer representing the length of the longest subarray with at most k distinct integers.

## sample

7 2
1 2 1 2 3 4 1

4

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