Sherlock and Smallest Window

Watson has infinite supply of K different type of objects denoted by numbers 1 to K. He makes an array A of N objects, A1, A2, ..., AN using these objects. Now, he'll update this array Q times. In ith update, he'll replace an existing object in array with a new object of different type from 1 to K i.e. Axi = yi. After each update, he wants Sherlock to report the smallest size of a contiguous sub