32 lines
922 B
Python
32 lines
922 B
Python
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"""
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Remove all duplicates from a string
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I/P: "bbaaccdefabafaz"
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O/P: "bacdefz"
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Time Complexity: O(n)
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Space Complexity: O(26) (constant)
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"""
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string = "bbaaccdefabafaz" # Constraint: only smallcase letters are there
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def remove_duplicate(string):
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alphabet = "0" * 26 # instead of going for classic use of sets, dictionaries we can use string containing bits. Either way is fine.
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ans_string = ""
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for letter in string:
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index = ord(letter)-ord('a')
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if index < 0 or index > 25:
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return ("Invalid")
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if alphabet[index] == "1":
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pass
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else:
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index = ord(letter)-ord('a')
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if index == 0:
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alphabet = "1" + alphabet[1:]
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else:
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alphabet = alphabet[0:index] + "1" + alphabet[index+1:]
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ans_string += letter
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return ans_string
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if __name__ == "__main__":
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print(remove_duplicate(string))
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