valid_palindrome.py (984B)
| # 125. Valid Palindrome
"""
a phrase is a palindrome if, after converting all uppercase letters into
lowercase letters, and removing all non-alphanumeric characters, it reads the
same forward and backward. alphanumeric characters include only letters and
numbers. given a string 's', return true if it is a palindrome, or false
otherwise.
"""
class Solution(object):
def isPalindrome(self, s):
"""
:type s: str
:rtype: bool
"""
l, r = 0, len(s) - 1
while l < r:
while l < r and not s[l].isalnum():
l += 1
while l < r and not s[r].isalnum():
r -= 1
if s[l].lower() != s[r].lower():
return False
l += 1
r -= 1
return True
if __name__ == "__main__":
obj = Solution()
print(obj.isPalindrome(s="A man, a plan, a canal: Panama"))
print(obj.isPalindrome(s="race a car"))
print(obj.isPalindrome(s=" "))
|
