Revert "Update 125-Valid-Palindrome.py"

125-Valid-Palindrome.py

@@ -1,17 +1,19 @@
 class Solution:
  def isPalindrome(self, s: str) -> bool:
- l = 0
- r = len(s)-1
- while l<r:
- if s[l].lower()==s[r].lower():
- l+=1
- r-=1
- continue
-
- elif not (65<=ord(s[l])<=90 or 97<=ord(s[l])<=122 or 48<=ord(s[l])<=57):
- l+=1
- elif not (65<=ord(s[r])<=90 or 97<=ord(s[r])<=122 or 48<=ord(s[r])<=57):
- r-=1
- else:
+ 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'))