This notebook was prepared by Donne Martin. Source and license info is on GitHub.
i k A = [1, 3, 5, 7, 9, None, None, None] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 5, 7, 9, None, None, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 5, 7, 9, None, 7, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 5, 7, 9, 6, 7, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 5, 7, 5, 6, 7, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 5, 5, 5, 6, 7, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) i k A = [1, 3, 4, 5, 5, 6, 7, 9] j B = [4, 5, 6] --- A[k] = max(A[i], B[j]) ik A = [1, 3, 4, 5, 5, 6, 7, 9] B = [4, 5, 6] --- A = [1, 3, 4, 5, 5, 6, 7, 9]
Complexity:
class Array(object):
def merge_into(self, source, dest, source_end_index, dest_end_index):
if source is None or dest is None:
raise TypeError('source or dest cannot be None')
if source_end_index < 0 or dest_end_index < 0:
raise ValueError('end indices must be >= 0')
if not source:
return dest
if not dest:
return source
source_index = source_end_index - 1
dest_index = dest_end_index - 1
insert_index = source_end_index + dest_end_index - 1
while dest_index >= 0:
if source[source_index] > dest[dest_index]:
source[insert_index] = source[source_index]
source_index -= 1
else:
source[insert_index] = dest[dest_index]
dest_index -= 1
insert_index -= 1
return source
%%writefile test_merge_into.py
import unittest
class TestArray(unittest.TestCase):
def test_merge_into(self):
array = Array()
self.assertRaises(TypeError, array.merge_into, None, None, None, None)
self.assertRaises(ValueError, array.merge_into, [1], [2], -1, -1)
a = [1, 2, 3]
self.assertEqual(array.merge_into(a, [], len(a), 0), [1, 2, 3])
a = [1, 2, 3]
self.assertEqual(array.merge_into(a, [], len(a), 0), [1, 2, 3])
a = [1, 3, 5, 7, 9, None, None, None]
b = [4, 5, 6]
expected = [1, 3, 4, 5, 5, 6, 7, 9]
self.assertEqual(array.merge_into(a, b, 5, len(b)), expected)
print('Success: test_merge_into')
def main():
test = TestArray()
test.test_merge_into()
if __name__ == '__main__':
main()
Overwriting test_merge_into.py
%run -i test_merge_into.py
Success: test_merge_into