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First solution in Clear category for Count Inversions by k0t9i.svinota
def count_inversion(sequence):
items = list(sequence)
num = 0
for i in reversed(range(len(items))):
for j in range(1, i + 1):
if items[j-1] > items[j]:
num += 1
items[j], items[j-1] = items[j-1], items[j]
return num
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. 9, 2016
