Given two strings s1 and s2, return true if s2 contains a permutation of s1. In other words, return true if one of s1's permutations is a 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
Explanation: No permutation of s1 exists as a contiguous substring in s2.
Example 3:
Input: s1 = "adc", s2 = "dcda"
Output: true
Explanation: s2 contains the permutation "dca" starting at index 1.
1 <= s1.length, s2.length <= 10⁴s1 and s2 consist of lowercase English letters only.