def test_partition(self):
pivot_index = sort.partition(0, len(self.list), self.list)
for e in self.list[0:pivot_index]:
self.assertGreaterEqual(self.list[pivot_index], e)
for e in self.list[pivot_index:]:
self.assertGreaterEqual(e, self.list[pivot_index])
def select(source, start, end, k):
if (end - start) <= 140:
sort.normal_quick_sort(source, start, end)
return [source[k - 1], k-1]
length = end - start
for i in xrange(length/5):
sort.insert_sort(source,start + i*5, start + i*5 + 5)
temp = source[start + i]
source[start + i] = source[start + 5*i + 2]
source[start + 5*i + 2] = temp
[i, index] = select(source, start, start + length/5, length/10)
temp = source[index]
source[index] = source[end - 1]
source[end - 1] = temp
j = sort.partition(source, start, end)
if j == k:
return [source[j], j]
elif j > k:
return select(source, start, j, k)
else:
return select(source, j + 1, end, k)
def select(source, start, end, k):
if (end - start) <= 140:
sort.normal_quick_sort(source, start, end)
return [source[k - 1], k - 1]
length = end - start
for i in xrange(length / 5):
sort.insert_sort(source, start + i * 5, start + i * 5 + 5)
temp = source[start + i]
source[start + i] = source[start + 5 * i + 2]
source[start + 5 * i + 2] = temp
[i, index] = select(source, start, start + length / 5, length / 10)
temp = source[index]
source[index] = source[end - 1]
source[end - 1] = temp
j = sort.partition(source, start, end)
if j == k:
return [source[j], j]
elif j > k:
return select(source, start, j, k)
else:
return select(source, j + 1, end, k)
def test_partion(self):
self.assertEqual(sort.partition([3, 7, 2, 1, 5, 4], 0, 5), 3)
def test_partitioning_when_sequence_with_duplicates_given():
sequence = ['A', 'A', 'B', 'B', 'A', 'B', 'A', 'A', 'A', 'B', 'A', 'A']
expected = ['A', 'A', 'A', 'A', 'A', 'A', 'B', 'A', 'B', 'B', 'B', 'A']
assert_equal(partition(sequence, lo=0, hi=len(sequence)-1), expected)
def test_partitioning():
assert_equal(partition([5, 4, 2, 11, 10], lo=0, hi=4), [2, 4, 5, 11, 10])
