import unittest
################################################################################
# Solution
################################################################################
# do_merge_ranges :: [(Int, Int)] -> [(Int, Int)] -> [(Int, Int)]
def do_merge_ranges(prev, xs):
if len(xs) == 0:
return prev
elif len(xs) == 1:
return prev + xs
else:
a1, a2 = xs[0]
b1, b2 = xs[1]
rest = xs[2:]
if b1 <= a2:
return do_merge_ranges(prev, [(a1, max(a2, b2))] + rest)
else:
return do_merge_ranges(prev + [(a1, a2)], [(b1, b2)] + rest)
# merge_ranges :: [(Int, Int)] -> [(Int, Int)]
def merge_ranges(xs):
xs = xs[:]
xs.sort()
return do_merge_ranges([], xs)
# merge_ranges_b :: [(Int, Int)] -> [(Int, Int)]
def merge_ranges_b(xs):
fi = 0
ci = 1
result = []
xs = xs[:]
xs.sort()
while ci < len(xs):
while ci < len(xs) and xs[ci][0] <= xs[fi][1]:
xs[fi] = xs[fi][0], max(xs[ci][1], xs[fi][1])
ci += 1
result.append(xs[fi])
fi = ci
ci += 1
if fi < len(xs):
result.append(xs[fi])
return result
################################################################################
# Tests
################################################################################
class Test(unittest.TestCase):
def test_meetings_overlap(self):
actual = merge_ranges([(1, 3), (2, 4)])
expected = [(1, 4)]
self.assertEqual(actual, expected)
def test_meetings_touch(self):
actual = merge_ranges([(5, 6), (6, 8)])
expected = [(5, 8)]
self.assertEqual(actual, expected)
def test_meeting_contains_other_meeting(self):
actual = merge_ranges([(1, 8), (2, 5)])
expected = [(1, 8)]
self.assertEqual(actual, expected)
def test_meetings_stay_separate(self):
actual = merge_ranges([(1, 3), (4, 8)])
expected = [(1, 3), (4, 8)]
self.assertEqual(actual, expected)
def test_multiple_merged_meetings(self):
actual = merge_ranges([(1, 4), (2, 5), (5, 8)])
expected = [(1, 8)]
self.assertEqual(actual, expected)
def test_meetings_not_sorted(self):
actual = merge_ranges([(5, 8), (1, 4), (6, 8)])
expected = [(1, 4), (5, 8)]
self.assertEqual(actual, expected)
def test_one_long_meeting_contains_smaller_meetings(self):
actual = merge_ranges([(1, 10), (2, 5), (6, 8), (9, 10), (10, 12)])
expected = [(1, 12)]
self.assertEqual(actual, expected)
def test_sample_input(self):
actual = merge_ranges([(0, 1), (3, 5), (4, 8), (10, 12), (9, 10)])
expected = [(0, 1), (3, 8), (9, 12)]
self.assertEqual(actual, expected)
unittest.main(verbosity=2)
