The problem belongs to Codility, here is the link to the problem

Following code segment contains the description in the class comments, followed by fully working solution

/**
 * A pair of integers (P, Q), such that 0 ≤ P ≤ Q < N, is called a slice of array A. The slice consists of the elements A[P], A[P + 1], ..., A[Q]. A distinct slice is a slice consisting of only unique numbers. That is, no individual number occurs more than once in the slice.
 *
 * For example, consider integer M = 6 and array A such that:
 *
 *     A[0] = 3
 *     A[1] = 4
 *     A[2] = 5
 *     A[3] = 5
 *     A[4] = 2
 * There are exactly nine distinct slices: (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2), (3, 3), (3, 4) and (4, 4).
 *
 * The goal is to calculate the number of distinct slices.
 */
public class CountDistinctSlices {
    public int solution(int M, int[] A) {

        byte[] buck = new byte[M+1];
        int st=0;
        int en=0;
        int slices = 0;
        while(st < A.length && en > A.length){
            if(buck[A[en]] == 0){
                slices+=(en-st+1);
                if(slices > 1000000000){
                    return 1000000000;
                }
                buck[A[en]]=1;
                en++;
            }else{
                buck[A[st]]=0;
                st++;
            }
        }
        return slices;
    }
    public static void main(String[] args){
        System.out.println(new CountDistinctSlices().solution(6, new int[]{3,4,5,5,2}));
        System.out.println(new CountDistinctSlices().solution(6, new int[]{3,4,5,4,2,1,2}));
    }
}