- Difficulty: Medium
- Tags: LeetCode, Medium, Trie, Array, Hash Table, Enumeration, Hash Function, Rolling Hash, leetcode-2261, O(n^2), O(t), Rabin-Karp Algorithm
Problem
Given an integer array nums
and two integers k
and p
, return the number of distinct subarrays, which have at most k
elements that are divisible by p
.
Two arrays nums1
and nums2
are said to be distinct if:
- They are of different lengths, or
- There exists at least one index
i
wherenums1[i] != nums2[i]
.
A subarray is defined as a non-empty contiguous sequence of elements in an array.
Example 1:
Input: nums = [2,3,3,2,2], k = 2, p = 2 Output: 11 Explanation: The elements at indices 0, 3, and 4 are divisible by p = 2. The 11 distinct subarrays which have at most k = 2 elements divisible by 2 are: [2], [2,3], [2,3,3], [2,3,3,2], [3], [3,3], [3,3,2], [3,3,2,2], [3,2], [3,2,2], and [2,2]. Note that the subarrays [2] and [3] occur more than once in nums, but they should each be counted only once. The subarray [2,3,3,2,2] should not be counted because it has 3 elements that are divisible by 2.
Example 2:
Input: nums = [1,2,3,4], k = 4, p = 1 Output: 10 Explanation: All element of nums are divisible by p = 1. Also, every subarray of nums will have at most 4 elements that are divisible by 1. Since all subarrays are distinct, the total number of subarrays satisfying all the constraints is 10.
Constraints:
1 <= nums.length <= 200
1 <= nums[i], p <= 200
1 <= k <= nums.length
Follow up:
Can you solve this problem in O(n2) time complexity?