substring.py

# 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 countSubsring(s):
    """
    :type s: str
    :rtype: int
    """
    count = 0

    def count_palindromes(left, right):
        local_count = 0
        while left >= 0 and right < len(s) and s[left] == s[right]:
            local_count += 1
            left -= 1
            right += 1
        return local_count
    
    for i in range(len(s)):
        count += count_palindromes(i, i)
        count += count_palindromes(i, i + 1)
    return count

s1 = "abc"
s2 = "aaa"

# Test cases
print(countSubsring(s1)) # # Output: 3
print(countSubsring(s2)) # Output: 6