Python/strings/is_contains_unique_chars.py

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def is_contains_unique_chars(input_str: str) -> bool:
"""
Check if all characters in the string is unique or not.
>>> is_contains_unique_chars("I_love.py")
True
>>> is_contains_unique_chars("I don't love Python")
False
Time complexity: O(n)
Space compexity: O(1) 19320 bytes as we are having 144697 characters in unicode
"""
# Each bit will represent each unicode character
# For example 65th bit representing 'A'
# https://stackoverflow.com/a/12811293
bitmap = 0
for ch in input_str:
ch_unicode = ord(ch)
ch_bit_index_on = pow(2, ch_unicode)
# If we already turned on bit for current character's unicode
if bitmap >> ch_unicode & 1 == 1:
return False
bitmap |= ch_bit_index_on
return True
if __name__ == "__main__":
import doctest
doctest.testmod()