An integer K and a non-empty array A consisting of N integers are given.
A pair of integers (P, Q), such that 0 ≤ P ≤ Q < N, is called a slice of array A.
A bounded slice is a slice in which the difference between the maximum and minimum values in the slice is less than or equal to K. More precisely it is a slice, such that max(A[P], A[P + 1], ..., A[Q]) − min(A[P], A[P + 1], ..., A[Q]) ≤ K.
The goal is to calculate the number of bounded slices.
For example, consider K = 2 and array A such that:
A[0] = 3 A[1] = 5 A[2] = 7 A[3] = 6 A[4] = 3There are exactly nine bounded slices: (0, 0), (0, 1), (1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3, 3), (4, 4).
Write a function:
class Solution { public int solution(int K, int[] A); }
that, given an integer K and a non-empty array A of N integers, returns the number of bounded slices of array A.
If the number of bounded slices is greater than 1,000,000,000, the function should return 1,000,000,000.
For example, given:
A[0] = 3 A[1] = 5 A[2] = 7 A[3] = 6 A[4] = 3the function should return 9, as explained above.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..100,000];
- K is an integer within the range [0..1,000,000,000];
- each element of array A is an integer within the range [−1,000,000,000..1,000,000,000].