Solved LC5_LongestPalindrome

aswinavofficial · aswinavofficial · commit bc175b45b5a2 · 2020-05-18T01:58:57.000+05:30
diff --git a/strings/LC125_isPalindrome/main.py b/strings/LC125_isPalindrome/main.py
@@ -5,15 +5,15 @@ def isPalindrome(self, s):
         :rtype: bool
         """
         import re
-        
-        s = re.sub(r'[\W_]','',s).lower()
-        
+
+        s = re.sub(r"[\W_]", "", s).lower()
+
         left = 0
         right = len(s) - 1
-        
+
         while left < right:
             if s[left] != s[right]:
                 return False
-            left = left +1
-            right = right -1
+            left = left + 1
+            right = right - 1
         return True
diff --git a/strings/LC5_longestPalindrome/main.py b/strings/LC5_longestPalindrome/main.py
@@ -4,5 +4,19 @@
 # longestPalindrome("abba") --> "abba"
 # longestPalindrome("a") --> "a"
 
+
 class Solution:
-    def longestPalindrome(self, s):
+    def retrieve_pal(self, s, left, right):
+        while left >= 0 and right < len(s) and s[left] == s[right]:
+            left = left - 1
+            right = right + 1
+        return s[left + 1 : right]
+
+    def longestPalindrome(self, s):
+        res = ""
+
+        for i in range(len(s)):
+            current = self.retrieve_pal(s, i - 1, i + 1)
+            in_between = self.retrieve_pal(s, i, i + 1)
+            res = max(current, in_between, res, key=len)
+        return res
