647. Palindromic Substrings

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.

 def countSubstrings(s):

   

    L = len(s)

    is_range_pal = [[False]*L for _ in range(L)]

   

    count = 0

    for i in range(L):

        is_range_pal[i][i] = True

        count += 1

       

    for cur in range(1, L):

        for start in range(0, cur):

            if s[start] == s[cur] and (is_range_pal[start+1][cur-1] or start+1 == cur):

                is_range_pal[start][cur] = True

                count += 1

               

    return count