229. Permutation in String

Given strings s1 and s2, return true if s2 contains a permutation of s1 as a contiguous substring. Input: '"s1", "s2"'.

Input: '"s1", "s2"'.

Output: Boolean — true or false.

Examples

Example 1

Input: "ab", "eidbaooo"
Output: true
Explanation: 'ba' is a permutation of 'ab'.

Example 2

Input: "ab", "eidboaoo"
Output: false
Explanation: No permutation window.

Example 3

Input: "a", "a"
Output: true
Explanation: Exact match.