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* return -1 if target is not in array * return -1 if target is not in array (python) * <= in binary search while loop
23 lines
711 B
Python
23 lines
711 B
Python
def binary_search(arr, target):
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left = 0;
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right = len(arr) - 1
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while left <= right:
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mid = left + (right - left) // 2;
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if arr[mid] == target:
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return mid
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elif arr[mid] < target:
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left = mid + 1
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else:
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right = mid - 1
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return -1
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print(binary_search([1, 2, 3, 10], 1) == 0)
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print(binary_search([1, 2, 3, 10], 2) == 1)
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print(binary_search([1, 2, 3, 10], 3) == 2)
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print(binary_search([1, 2, 3, 10], 10) == 3)
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print(binary_search([1, 2, 3, 10], 9) == -1)
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print(binary_search([1, 2, 3, 10], 4) == -1)
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print(binary_search([1, 2, 3, 10], 0) == -1)
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print(binary_search([1, 2, 3, 10], 11) == -1)
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print(binary_search([5, 7, 8, 10], 3) == -1)
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