Скачать или смотреть Count distinct elements in every window (Python)

Given an array of integers and a number k, print the count of distinct elements in every window of size k.

For example, consider the following array and k = 3

arr[] = {1, 2, 1, 3, 4, 2, 3, 4, 1}
Output: 3 4 4 3

There are 3 distinct elements in the first window (1, 2, 1),
4 distinct elements in the second window (2, 1, 3, 4),
4 distinct elements in the third window (1, 3, 4, 2),
3 distinct elements in the fourth window (3, 4, 1)

There are two ways to do this.

Method 1:

The idea is to use a hash map to store the count of distinct elements in each window. The count of distinct elements in the first window can be easily found out.

For the next window, we add a new element and remove an old one, so the count of distinct element changes by 1. We keep track of this change by maintaining a hash map.

We also maintain a variable distinct_count to store the count of distinct elements in the current window.