The array a [a1, a2, .., an] is given. The task is to find the number of subarrays, where a[l]'s and a[r]'s values are unique in the a[l], a[l + 1], ... , a[r] subarray, so a[l] and a[r] are repeating only once in that subarray. Sorry for bad English, here is the link: https://uoisel25.eolymp.space/ru/compete/bqludneu0t4rj8prhu3ru25j9c/problem/2