Hackerrank: Palindrome Index Solution

1function palindromeIndex(s) {
2  function isPalindrome(s) {
3    for (let i = 0; i < Math.floor(s.length / 2); i++) {
4      if (s[i] !== s[s.length - i - 1]) {
5        return false
6      }
7    }
8    return true
9  }
10
11  let res = -1
12
13  for (let i = 0; i < Math.floor(s.length / 2); i++) {
14    if (s[i] !== s[s.length - i - 1]) {
15      const tmp = s.substring(0, i) + s.substring(i + 1)
16      if (isPalindrome(tmp)) {
17        return i
18      } else {
19        return s.length - i - 1
20      }
21    }
22  }
23
24  return -1
25}