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38 lines
1.1 KiB
Python
38 lines
1.1 KiB
Python
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from typing import List
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def double_linear_search(array: List[int], search_item: int) -> int:
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"""
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Iterate through the array from both sides to find the index of search_item.
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:param array: the array to be searched
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:param search_item: the item to be searched
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:return the index of search_item, if search_item is in array, else -1
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Examples:
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>>> double_linear_search([1, 5, 5, 10], 1)
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0
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>>> double_linear_search([1, 5, 5, 10], 5)
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1
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>>> double_linear_search([1, 5, 5, 10], 100)
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-1
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>>> double_linear_search([1, 5, 5, 10], 10)
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3
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"""
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# define the start and end index of the given array
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start_ind, end_ind = 0, len(array) - 1
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while start_ind <= end_ind:
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if array[start_ind] == search_item:
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return start_ind
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elif array[end_ind] == search_item:
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return end_ind
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else:
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start_ind += 1
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end_ind -= 1
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# returns -1 if search_item is not found in array
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return -1
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if __name__ == "__main__":
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print(double_linear_search(list(range(100)), 40))
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