40 lines
917 B
Python
40 lines
917 B
Python
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"""
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Algorithm Type: Array sorting with 0s,1s and 2s in a single pass
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Explain: To separate three different groups
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Time Complexity: O(n)
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Space Complexity: O(1)
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0 0 1 1 1 ? ? ? ? 2 2
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v v v
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Low Mid High
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To goal of the algo is to shrink this '?' region
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wrapped by Mid and High
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> Low starts at 1
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"""
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numbers = [2, 0, 1, 1, 2, 0, 1, 2]
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def DNFS(numbers: list) -> list:
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length = len(numbers)
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low = 0
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high = length - 1
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mid = 0
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while mid <= high:
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if numbers[mid] == 0:
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numbers[low], numbers[mid] = numbers[mid], numbers[low]
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low = low + 1
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mid = mid + 1
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elif numbers[mid] == 1:
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mid = mid + 1
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else:
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numbers[mid], numbers[high] = numbers[high], numbers[mid]
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high = high - 1
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return numbers
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if __name__ == "__main__":
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print(DNFS(numbers))
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