567\. Permutation in String

Medium

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`.

**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:**

*   <code>1 <= s1.length, s2.length <= 10<sup>4</sup></code>
*   `s1` and `s2` consist of lowercase English letters.