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1f8a21d727
* Tighten up psf/black and flake8
* Fix some tests
* Fix some E741
* Fix some E741
* updating DIRECTORY.md
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
49 lines
951 B
Python
49 lines
951 B
Python
def merge(a, b, m, e):
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l = a[b : m + 1] # noqa: E741
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r = a[m + 1 : e + 1]
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k = b
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i = 0
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j = 0
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while i < len(l) and j < len(r):
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# change sign for Descending order
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if l[i] < r[j]:
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a[k] = l[i]
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i += 1
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else:
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a[k] = r[j]
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j += 1
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k += 1
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while i < len(l):
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a[k] = l[i]
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i += 1
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k += 1
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while j < len(r):
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a[k] = r[j]
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j += 1
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k += 1
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return a
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def mergesort(a, b, e):
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"""
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>>> mergesort([3,2,1],0,2)
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[1, 2, 3]
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>>> mergesort([3,2,1,0,1,2,3,5,4],0,8)
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[0, 1, 1, 2, 2, 3, 3, 4, 5]
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"""
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if b < e:
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m = (b + e) // 2
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# print("ms1",a,b,m)
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mergesort(a, b, m)
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# print("ms2",a,m+1,e)
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mergesort(a, m + 1, e)
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# print("m",a,b,m,e)
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merge(a, b, m, e)
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return a
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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