def test_count_sorted(self):
items = [1, 2, 3, 4, 5]
# merge sort only
inv = Inversions(items, 0)
self.assertEqual(inv.count(), 0)
# insertion sort only
inv = Inversions(items)
self.assertEqual(inv.count(), 0)
# mixed
inv = Inversions(items, 2)
self.assertEqual(inv.count(), 0)
def test_count_reversed(self):
items = [5, 4, 3, 2, 1]
# merge sort only
inv = Inversions(items, 0)
self.assertEqual(inv.count(), 10)
# insertion sort only
inv = Inversions(items)
self.assertEqual(inv.count(), 10)
# mixed
inv = Inversions(items, 2)
self.assertEqual(inv.count(), 10)
def test_count_split_inversions(self):
items = [1, 4, 6, 5, 2]
# (4,2) (6,5) (6,2) (5,2)
# merge sort only
inv = Inversions(items, 0)
self.assertEqual(inv.count(), 4)
# insertion sort only
inv = Inversions(items)
self.assertEqual(inv.count(), 4)
# mixed
inv = Inversions(items, 2)
self.assertEqual(inv.count(), 4)
def test_count_side_inversions(self):
items = [1, 2, 4, 3]
# (4,3)
# merge sort only
inv = Inversions(items, 0)
self.assertEqual(inv.count(), 1)
# insertion sort only
inv = Inversions(items)
self.assertEqual(inv.count(), 1)
# mixed
inv = Inversions(items, 2)
self.assertEqual(inv.count(), 1)
#!/usr/bin/env python3
import argparse
import random
import sys
from inversions import Inversions
parser = argparse.ArgumentParser(description='Inversions client.')
group = parser.add_mutually_exclusive_group()
group.add_argument('-b', '--bound', type=int, help='Upper bound number')
group.add_argument('infile', nargs='?', type=argparse.FileType('r'),
default=sys.stdin,
help='Input file with numbers (default stdin)')
args = parser.parse_args()
if args.bound is not None:
nums = list(range(1, args.bound+1))
random.shuffle(nums)
else:
nums = [int(num) for num in args.infile]
inv = Inversions(nums)
print(inv.count())
