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First solution in Clear category for Count Inversions by Degusto
def count_inversion(sequence):
inversion_count = 0
sequence = list(sequence)
for i in range(len(sequence)):
j = i + 1
while j < len(sequence):
if sequence[i] > sequence[j]:
inversion_count += 1
(sequence[i], sequence[j]) = (sequence[j], sequence[i])
j += 1
return inversion_count
if __name__ == '__main__':
#These "asserts" using only for self-checking and not necessary for auto-testing
assert count_inversion((1, 2, 5, 3, 4, 7, 6)) == 3, "Example"
assert count_inversion((0, 1, 2, 3)) == 0, "Sorted"
assert count_inversion((99, -99)) == 1, "Two numbers"
assert count_inversion((5, 3, 2, 1, 0)) == 10, "Reversed"
Nov. 18, 2015
