#### Permutationin String

P
```/**
*  @name The-Sliding-Window Algorithm is primarily used for the problems dealing with linear data structures like Arrays, Lists, Strings etc.
*  These problems can easily be solved using Brute Force techniques which result in quadratic or exponential time complexity.
*  Sliding window technique reduces the required time to linear O(n).
*  @see [The-Sliding-Window](https://www.geeksforgeeks.org/window-sliding-technique/)
*/
/**
* @function PermutationinString
* @description Given two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise.
* @param {String} s1 - The input string
* @param {String} s2 - The input string
* @return {boolean} - Returns true if s2 contains a permutation of s1, or false otherwise.
*/

export function PermutationinString(s1, s2) {
if (s1.length > s2.length) return false
let start = 0
let end = s1.length - 1
const s1Set = SetHash()
const s2Set = SetHash()
for (let i = 0; i < s1.length; i++) {
s1Set[s1[i]]++
s2Set[s2[i]]++
}
if (equals(s1Set, s2Set)) return true
while (end < s2.length - 1) {
if (equals(s1Set, s2Set)) return true
end++
const c1 = s2[start]
const c2 = s2[end]
if (s2Set[c1] > 0) s2Set[c1]--
s2Set[c2]++
start++
if (equals(s1Set, s2Set)) return true
}
return false
}
function equals(a, b) {
return JSON.stringify(a) === JSON.stringify(b)
}

function SetHash() {
const set = new Set()
const alphabets = 'abcdefghijklmnopqrstuvwxyz'
for (let i = 0; i < alphabets.length; i++) {
set[alphabets[i]] = 0
}
return set
}

// 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
```