notes/OJ notes/pages/Leetcode Permutation-In-String.md

Leetcode Permutation-In-String

2022-07-14 10:29

Algorithms:

#algorithm #sliding_window

Data structures:

#DS #string

Difficulty:

#coding_problem #difficulty-medium

Additional tags:

#leetcode #CS_list_need_understanding

Revisions:

N/A

Related topics:

tag:#sliding_window

Links:

• Link to problem

---

Problem

Given two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise.

In other words, return true if one of s1's permutations is the substring of s2.

Examples

Example 1:

Input: s1 = "ab", s2 = "eidbaooo" Output: true Explanation: s2 contains one permutation of s1 ("ba").

Example 2:

Input: s1 = "ab", s2 = "eidboaoo" Output: false

Constraints

• 1 <= s1.length, s2.length <= 104
• s1 and s2 consist of lowercase English letters.

Thoughts

[!summary] This is a #sliding_window problem.

I tried to use kadane's algorithm, but the problem is a premature string, not set. So I gave up.

Solution