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First solution in Uncategorized category for Count Inversions by ChubinOleg
def count_inversion(sequence):
"""
Count inversions in a sequence of numbers
"""
sequence = list(sequence)
def swap(i, j):
sequence[i], sequence[j] = sequence[j], sequence[i]
result = 0
i = 0
while i < len(sequence) - 1:
if sequence[i] > sequence[i + 1]:
swap(i, i + 1)
i = 0
result += 1
else:
i += 1
return result
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"
Oct. 25, 2014
