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57 lines
1.4 KiB
Python
57 lines
1.4 KiB
Python
"""
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This is pure python implementation of sentinel linear search algorithm
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For doctests run following command:
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python -m doctest -v sentinel_linear_search.py
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or
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python3 -m doctest -v sentinel_linear_search.py
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For manual testing run:
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python sentinel_linear_search.py
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"""
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def sentinel_linear_search(sequence, target):
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"""Pure implementation of sentinel linear search algorithm in Python
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:param sequence: some sequence with comparable items
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:param target: item value to search
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:return: index of found item or None if item is not found
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Examples:
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>>> sentinel_linear_search([0, 5, 7, 10, 15], 0)
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0
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>>> sentinel_linear_search([0, 5, 7, 10, 15], 15)
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4
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>>> sentinel_linear_search([0, 5, 7, 10, 15], 5)
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1
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>>> sentinel_linear_search([0, 5, 7, 10, 15], 6)
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"""
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sequence.append(target)
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index = 0
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while sequence[index] != target:
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index += 1
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sequence.pop()
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if index == len(sequence):
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return None
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return index
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if __name__ == '__main__':
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user_input = input('Enter numbers separated by comma:\n').strip()
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sequence = [int(item) for item in user_input.split(',')]
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target_input = input('Enter a single number to be found in the list:\n')
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target = int(target_input)
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result = sentinel_linear_search(sequence, target)
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if result is not None:
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print('{} found at positions: {}'.format(target, result))
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else:
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print('Not found') |