Q sort

q_sort.py

@@ -0,0 +1,60 @@
+from merge_sort import timed_func
+
+
+def q_sort(sequence):
+    if len(sequence) <= 1:
+        # Return a sequence of one sorted item, or stop if no input
+        return sequence
+    if len(sequence) == 2:
+        # Return a sequence of two sorted items
+        if sequence[1] > sequence[0]:
+            return sequence
+        else:
+            return sequence[::-1]
+    pivot = get_pivot(sequence)
+    left = []
+    right = []
+    center = []
+    for index, item in enumerate(sequence):
+        if item < pivot:
+            left.append(item)
+        elif item > pivot:
+            right.append(item)
+        else:
+            center.append(item)
+    return q_sort(left) + center + q_sort(right)
+
+
+def get_pivot(sequence):
+    first = sequence[0]
+    last = sequence[-1]
+    mid_index = len(sequence) // 2
+    middle = sequence[mid_index]
+
+    if last > first > middle or middle > first > last:
+        return first
+    if last > middle > first or first > middle > last:
+        return middle
+    return last
+
+
+
+@timed_func
+def timed_q_sort(sequence):
+    return q_sort(sequence)
+
+
+def same_maker(how_many):
+    moAr = []
+    for each in range(how_many):
+        moAr.append(1)
+    return moAr
+
+
+if __name__ == '__main__':
+    inputs = [range(500), range(1000)]
+    inputs.append(same_maker(500))
+    inputs.append(same_maker(997))
+
+    for inp in inputs:
+        timed_q_sort(inp)

test_q_sort.py

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+from q_sort import get_pivot, q_sort
+
+
+def test_get_pivot_f():
+    a = [2, 1, 3]
+    assert get_pivot(a) == 2
+    b = [2, 3, 1]
+    assert get_pivot(b) == 2
+
+
+def test_get_pivot_l():
+    a = [1, 3, 2]
+    assert get_pivot(a) == 2
+    b = [3, 1, 2]
+    assert get_pivot(b) == 2
+
+
+def test_get_pivot_m():
+    a = [1, 5, 5, 2, 1, 1, 3]
+    assert get_pivot(a) == 2
+    b = [3, 2, 1]
+    assert get_pivot(b) == 2
+
+
+def test_q_one():
+    a = [4, 3, 2, 5, 7, 1, 6]
+    a = q_sort(a)
+    assert a == sorted(a)
+
+
+
+def test_q_two():
+    a = [5, 5, 5, 5, 5, 5, 5, 5, 5]
+    a = q_sort(a)
+    assert a == sorted(a)
+
+
+def test_q_mixed():
+    a = [1, 2, 5, 4, 4, 6, 7, 9, 8, 10, 10]
+    a = q_sort(a)
+    assert a == sorted(a)
+
+
+def test_q_mixed_duplicate_last_values_greater():
+    a = [1, 2, 10, 10, 10]
+    a = q_sort(a)
+    assert a == sorted(a)
+
+
+def test_q_mixed_duplicate_last_values_lesser():
+    a = [1, 2, 5, 0, 0]
+    a = q_sort(a)
+    assert a == sorted(a)
+
+
+def test_q_mixed():
+    a = [1, 2, 5, 4, 4, 6, 7, 9, 8, 0, 0]
+    a = q_sort(a)
+    assert a == [0, 0, 1, 2, 4, 4, 5, 6, 7, 8, 9]