26 lines
967 B
Python
26 lines
967 B
Python
def count_inversion(sequence):
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"""
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Count inversions in a sequence of numbers
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"""
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sequence = list(sequence)
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ordered_sequence = sorted(sequence)
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inversions = 0
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for index, number in enumerate(ordered_sequence):
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if sequence.index(number) == index:
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continue
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inversions += sequence.index(number) - index
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sequence.insert(index, sequence.pop(sequence.index(number)))
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return inversions
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if __name__ == '__main__':
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print("Example:")
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print(count_inversion([1, 2, 5, 3, 4, 7, 6]))
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# These "asserts" using only for self-checking and not necessary for auto-testing
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assert count_inversion((1, 2, 5, 3, 4, 7, 6)) == 3, "Example"
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assert count_inversion((0, 1, 2, 3)) == 0, "Sorted"
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assert count_inversion((5, 3, 2, 1, 0)) == 10, "Reversed"
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assert count_inversion((99, -99)) == 1, "Two numbers"
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print("Coding complete? Click 'Check' to review your tests and earn cool rewards!")
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