Find Beautiful Indices in the Given Array II

Find Beautiful Indices in the Given Array II is a Hard Data Structures and Algorithms interview problem you can solve, run and submit on Thita.ai. It belongs to the String Manipulation Patterns pattern, in the Naive / KMP / Rabin-Karp subpattern.

Problem statement

You are given a 0-indexed string s, a string a, a string b, and an integer k.

An index i is beautiful if:

- 0 <= i <= s.length - a.length

- s[i..(i + a.length - 1)] == a

- There exists an index j such that:

- 0 <= j <= s.length - b.length

- s[j..(j + b.length - 1)] == b

- |j - i| <= k

Return the array that contains beautiful indices in sorted order from smallest to largest.

Example 1:

Input: s = "isawsquirrelnearmysquirrelhouseohmy", a = "my", b = "squirrel", k = 15 Output: [16,33] Explanation: There are 2 beautiful indices: [16,33]. - The index 16 is beautiful as s[16..17] == "my" and there exists an index 4 with s[4..11] == "squirrel" and |16 - 4| <= 15. - The index 33 is beautiful as s[33..34] == "my" and there exists an index 18 with s[18..25] == "squirrel" and |33 - 18| <= 15. Thus we return [16,33] as the result.

Example 2:

Input: s = "abcd", a = "a", b = "a", k = 4 Output: [0] Explanation: There is 1 beautiful index: [0]. - The index 0 is beautiful as s[0..0] == "a" and there exists an index 0 with s[0..0] == "a" and |0 - 0| <= 4. Thus we return [0] as the result.

Constraints:

- 1 <= k <= s.length <= 5 105

- 1 <= a.length, b.length <= 5 105

- s, a, and b contain only lowercase English letters.

Topics and companies

Topics: Two Pointers, String, Binary Search, Rolling Hash, String Matching, Hash Function.

How to practise Find Beautiful Indices in the Given Array II on Thita.ai

Starter code is provided in C, C#, C++, Go, Java, JavaScript and Python. Your solution runs against 5 test cases for this problem, with the AI coach available for a hint when you are stuck rather than a finished answer. The reference solution runs in O(n), x = len(KMP(s, a)), y = len(KMP(s, b)) time and O(min(a + b + x + y, n)) space.

Open Find Beautiful Indices in the Given Array II in the code editor, or read the Find Beautiful Indices in the Given Array II editorial for a worked solution with its approach and complexity analysis.

Where Find Beautiful Indices in the Given Array II sits in the DSA pattern sheet

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