feat: add palindromic substrings solution

Author: mangodm-web

palindromic-substrings/dm.py

@@ -0,0 +1,23 @@
+class Solution:
+    def countPalindrome(self, s: str, left: int, right: int) -> int:
+        result = 0
+
+        while left >= 0 and right < len(s) and s[left] == s[right]:
+            result += 1
+            left -= 1
+            right += 1
+
+        return result
+
+    def countSubstrings(self, s: str) -> int:
+        total_count = 0
+
+        for i in range(len(s)):
+            left = right = i
+            total_count += self.countPalindrome(s, left, right)
+
+        for i in range(len(s) - 1):
+            left, right = i, i + 1
+            total_count += self.countPalindrome(s, left, right)
+
+        return total_count