# Algorithms to determine if a string is palindrome

test_data = {
 "MALAYALAM": True,
 "String": False,
 "rotor": True,
 "level": True,
 "A": True,
 "BB": True,
 "ABC": False,
 "amanaplanacanalpanama": True, # "a man a plan a canal panama"
}
# Ensure our test data is valid
assert all((key == key[::-1]) is value for key, value in test_data.items())


def is_palindrome(s: str) -> bool:
 """
 Return True if s is a palindrome otherwise return False.

 >>> all(is_palindrome(key) is value for key, value in test_data.items())
 True
 """

 start_i = 0
 end_i = len(s) - 1
 while start_i < end_i:
 if s[start_i] == s[end_i]:
 start_i += 1
 end_i -= 1
 else:
 return False
 return True


def is_palindrome_recursive(s: str) -> bool:
 """
 Return True if s is a palindrome otherwise return False.

 >>> all(is_palindrome_recursive(key) is value for key, value in test_data.items())
 True
 """
 if len(s) <= 1:
 return True
 if s[0] == s[len(s) - 1]:
 return is_palindrome_recursive(s[1:-1])
 else:
 return False


def is_palindrome_slice(s: str) -> bool:
 """
 Return True if s is a palindrome otherwise return False.

 >>> all(is_palindrome_slice(key) is value for key, value in test_data.items())
 True
 """
 return s == s[::-1]


if __name__ == "__main__":
 for key, value in test_data.items():
 assert is_palindrome(key) is is_palindrome_recursive(key)
 assert is_palindrome(key) is is_palindrome_slice(key)
 print(f"{key:21}{value}")
 print("a man a plan a canal panama")