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47 lines
959 B
Python
47 lines
959 B
Python
#!/usr/bin/env python
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# AKA: do you believe in magic?
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__author__ = "bt3"
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def merge_sort(array):
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if len(array) < 2:
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return array
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# divide
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mid = len(array)//2
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left = merge_sort(array[:mid])
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right = merge_sort(array[mid:])
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# merge
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result = []
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i, j = 0, 0
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while i < len(left) and j < len(right):
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if left[i] < right[j]:
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result.append(left[i])
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i += 1
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else:
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result.append(right[j])
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j+= 1
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# make sure nothing is left behind
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if left[i:]:
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result.extend(left[i:])
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if right[j:]:
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result.extend(right[j:])
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return result
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if __name__ == '__main__':
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array = [3, 1, 6, 0, 7, 19, 7, 2, 22]
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sorted = [0, 1, 2, 3, 6, 7, 7, 19, 22]
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assert(merge_sort(array) == sorted)
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array = []
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assert(merge_sort(array) == array)
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array = [1]
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assert(merge_sort(array) == array) |