def randomized_partition(array, p, r):
"""
随机选择主元版
"""
i = random_utils.random_int(p, r)
array_utils.exchange(array, i, r)
return partition(array, p, r)
def heap_increase_key(queue, x, key):
if key < queue[x]:
print("new key is smaller than current key")
return
queue[x] = key
while x > 0 and queue[max_heap_sort.parent(x)] < queue[x]:
array_utils.exchange(queue, max_heap_sort.parent(x), x)
x = max_heap_sort.parent(x)
def partition_by_desc(array, p, r):
x = array[r]
i = p - 1
for j in range(p, r, 1):
if array[j] >= x:
i += 1
array_utils.exchange(array, i, j)
array_utils.exchange(array, i + 1, r)
return i + 1
def partition(arr, p, r, x):
# 先将主元x放置到位置r处
for j in range(p, r + 1):
if arr[j] == x:
array_utils.exchange(arr, j, r)
break
i = p - 1
for j in range(p, r, 1):
if arr[j] <= x:
i += 1
array_utils.exchange(arr, i, j)
array_utils.exchange(arr, i + 1, r)
return i + 1
def randomized_partition(arr, p, r):
i = random_utils.random_int(p, r)
array_utils.exchange(arr, i, r)
return partition(arr, p, r)