Given a string s, return the number of palindromic substrings in it.
A string is a palindrome when it reads the same backward as forward. A substring is a contiguous sequence of characters within the string.
Example 1:
Input: abc Output: 3
("a", "b", "c")
Example 2:
Input: aaa Output: 6
("a", "a", "a", "aa", "aa", "aaa")
Constraints:
- 1 ≤ s.length ≤ 1000
- s consists of lowercase English letters
Input format: A single string.
Output format: Count of palindromic substrings.