[Leo] 11th Week solutions

Author: leokim0922

palindromic-substrings/Leo.py

@@ -0,0 +1,19 @@
+class Solution:
+    def countSubstrings(self, s: str) -> int:
+        result = 0
+
+        def helper(left, right):
+            count = 0
+            while left >= 0 and right < len(s) and s[left] == s[right]:
+                count += 1
+                left -= 1
+                right += 1
+            return count
+
+        for i in range(len(s)):
+            result += helper(i, i)
+            result += helper(i, i + 1)
+
+        return result
+
+        ## TC: O(n^2), SC: O(1)