67 lines
2.1 KiB
Python
67 lines
2.1 KiB
Python
import string
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import math
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# def isPalindrome(s):
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# """
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# :type s: str
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# :rtype: bool
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# """
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# # Create a translation table to remove uppercase letters and special characters
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# # translation_table = str.maketrans("","", string.punctuation + string.whitespace)
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# translation_table = ''.join(c.lower() if c.isupper() or c.isalnum() else '' for c in s if c.isalnum() or c in string.whitespace)
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# # print(translation_table)
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# if len(translation_table) == 2:
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# if translation_table[0] == translation_table[1]:
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# return True
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# else:
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# return False
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# # Use the translation table to remove uppercase letters and special characters
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# # upper_string = s.translate(translation_table)
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# # lower_string = upper_string.lower()
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# lower_string = translation_table
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# half = len(lower_string)/2
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# # Round the value down since middle value doesn't matter
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# if len(lower_string)%2 != 0:
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# halfdown = int(math.floor(half))
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# else:
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# halfdown = int(half)
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# # print(halfup)
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# # print(halfdown)
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# first = []
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# second = []
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# print(lower_string)
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# for i in range(halfdown):
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# # print(i)
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# # print(lower_string[i])
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# first.append(lower_string[i])
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# if len(lower_string)%2 != 0:
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# for j in range(halfdown+1, len(lower_string)):
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# second.insert(0, lower_string[j])
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# else:
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# for j in range(halfdown, len(lower_string)):
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# second.insert(0, lower_string[j])
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# print(first)
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# print(second)
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# if first == second:
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# return True
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# else:
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# return False
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#Fastest solution
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# Operator ~ is the bitwise NOT operator (~x == -x-1 => ~0 == -1 => ~1 == -2 and etc),
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# which expects just one argument. It performs logical negation on a given number by
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# flipping all of its bits:
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def isPalindrome(s: str) -> bool:
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s = [c.lower() for c in s if c.isalnum()]
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return all (s[i] == s[~i] for i in range(len(s)//2))
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print(isPalindrome("A man, a plan, a canal: Panama"))
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print(isPalindrome("aa"))
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print(isPalindrome("0P"))
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print(isPalindrome("abba")) |