cpp-flashcards/org/study_deck_02/dsa/1-d-dynamic-programming/0647-palindromic-substrings.org

#+ANKI_DECK: study_deck_02
* TODO 0647. Palindromic Substrings :medium:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*0647. Palindromic Substrings][0647. Palindromic Substrings]]
:END:

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:*


#+begin_src
Input: s = "abc"
Output: 3
Explanation: Three palindromic strings: "a", "b", "c".
#+end_src


*Example 2:*


#+begin_src
Input: s = "aaa"
Output: 6
Explanation: Six palindromic strings: "a", "a", "a", "aa", "aa", "aaa".
#+end_src


*Constraints:*

 - ~1 <= s.length <= 1000~

 - ~s~ consists of lowercase English letters.

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python :lc-problem 647 :lc-lang python3
class Solution:
    def countSubstrings(self, s: str) -> int:
#+end_src

** TODO C++
#+begin_src cpp :lc-problem 647
class Solution {
public:
    int countSubstrings(string s) {
        
    }
};
#+end_src