def test_swap_array_size_2(self):
arr = [1, 2]
swap(arr, 0, 1)
assert arr[0] == 2
assert arr[1] == 1
def test_reswap(self):
arr = [1, 2]
swap(arr, 0, 1)
swap(arr, 0, 1)
assert arr[0] == 1
assert arr[1] == 2
def selectionsort(arr):
'''
Partition array into an unsorted and sorted portion.
Find smallest value in unsorted portion and place at end of sorted.
Time complexity: O(n^2), for all cases
O(n^2)
O(n^2)
Space complexity: O(1)
Use case: n<100 since it's slow but simple.
Probably would use insertionsort instead though.
'''
n = len(arr)
for i in range(n):
# Find index of minimum
minidx = i
for j in range(i + 1, n):
if arr[j] < arr[minidx]:
minidx = j
arr = swap(arr, minidx, i)
return arr
def bubble_up(self, k):
if k == 0:
return
if self.arr[self.parent(k)] > self.arr[k]:
self.arr = swap(self.arr, self.parent(k), k)
self.bubble_up(self.parent(k))
def insertionsort(arr):
'''
Partition array into an unsorted and sorted portion.
Take first value in unsorted portion,and move it to lower indices
until it is smaller than the value above it.
Time complexity: O(n^2), array is reversed
O(n^2),
O(n) , array is in order
Space complexity: O(1)
Use case: n<100 since it's slow but simple
'''
n = len(arr)
for i in range(1, n):
j = i
while j > 0 and arr[j] < arr[j - 1]:
swap(arr, j, j - 1)
j -= 1
return arr
def bubble_down(self, k):
c = 2 * k # Child index
min_idx = k
for i in range(2):
if (c + i) <= self.get_keys() - 1: # Check still in heap
if self.arr[min_idx] > self.arr[
c + i]: # if current value larger than child
min_idx = c + i
# If found one smaller
if min_idx != k:
self.arr = swap(self.arr, k, min_idx) # Swap them
self.bubble_down(
min_idx) # Then bubble_down same value at new index
def bubblesort(arr):
'''
Time complexity: O(n^2) Backwards, so every key is compared to every other key.
O(n^2) On average, 50/50 chance of two elements being out of order
O(n), already sorted
Space complexity: O(1), only reading two values at a time
'''
n = len(arr)
for i in range(n):
swapped = False
for j in range(0, n - i - 1):
if arr[j] > arr[j + 1]:
arr = swap(arr, j, j + 1)
swapped = True
# Stop sorting if nothing was swapped
if swapped == False:
break
return arr