Create 125-Valid-Palindrome.py

Author: neetcode-gh

125-Valid-Palindrome.py

@@ -0,0 +1,19 @@
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+        l, r = 0, len(s) - 1
+        while l < r:
+            while l < r and not self.alphanum(s[l]): 
+                l += 1
+            while l < r and not self.alphanum(s[r]): 
+                r -= 1
+            if s[l].lower() != s[r].lower(): 
+                return False
+            l += 1
+            r -= 1
+        return True
+    
+    # Could write own alpha-numeric function
+    def alphanum(self, c):
+        return (ord('A') <= ord(c) <= ord('Z') or
+                ord('a') <= ord(c) <= ord('z') or
+                ord('0') <= ord(c) <= ord('9'))