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Array-MinHeapSort.py
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99 lines (79 loc) · 3.44 KB
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class MinHeap:
def __init__(self):
self.min_heap = []
def peek(self) -> int:
# 大顶堆为空
if not self.min_heap:
return None
# 返回堆顶元素
return self.min_heap[0]
def push(self, val: int):
# 将新元素添加到堆的末尾
self.min_heap.append(val)
size = len(self.min_heap)
# 从新插入的元素节点开始,进行上移调整
self.__shift_up(size - 1)
def __shift_up(self, i: int):
while (i - 1) // 2 >= 0 and self.min_heap[i] < self.min_heap[(i - 1) // 2]:
self.min_heap[i], self.min_heap[(i - 1) // 2] = self.min_heap[(i - 1) // 2], self.min_heap[i]
i = (i - 1) // 2
def pop(self) -> int:
# 堆为空
if not self.min_heap:
raise IndexError("堆为空")
size = len(self.min_heap)
self.min_heap[0], self.min_heap[size - 1] = self.min_heap[size - 1], self.min_heap[0]
# 删除堆顶元素
val = self.min_heap.pop()
# 节点数减 1
size -= 1
self.__shift_down(0, size)
# 返回堆顶元素
return val
def __shift_down(self, i: int, n: int):
while 2 * i + 1 < n:
# 左右子节点编号
left, right = 2 * i + 1, 2 * i + 2
# 找出左右子节点中的较大值节点编号
if 2 * i + 2 >= n:
# 右子节点编号超出范围(只有左子节点
larger = left
else:
# 左子节点、右子节点都存在
if self.min_heap[left] <= self.min_heap[right]:
larger = left
else:
larger = right
# 将当前节点值与其较小的子节点进行比较
if self.min_heap[i] > self.min_heap[larger]:
# 如果当前节点值小于其较大的子节点,则将它们交换
self.min_heap[i], self.min_heap[larger] = self.min_heap[larger], self.min_heap[i]
i = larger
else:
# 如果当前节点值大于等于于其较大的子节点,此时结束
break
def __buildMinHeap(self, nums: [int]):
size = len(nums)
# 先将数组 nums 的元素按顺序添加到 min_heap 中
for i in range(size):
self.min_heap.append(nums[i])
# 从最后一个非叶子节点开始,进行下移调整
for i in range((size - 2) // 2, -1, -1):
self.__shift_down(i, size)
def minHeapSort(self, nums: [int]) -> [int]:
# 根据数组 nums 建立初始堆
self.__buildMinHeap(nums)
size = len(self.min_heap)
for i in range(size - 1, -1, -1):
# 交换根节点与当前堆的最后一个节点
self.min_heap[0], self.min_heap[i] = self.min_heap[i], self.min_heap[0]
# 从根节点开始,对当前堆进行下移调整
self.__shift_down(0, i)
# 返回排序后的数组
return self.min_heap
class Solution:
def minHeapSort(self, nums: [int]) -> [int]:
return MinHeap().minHeapSort(nums)
def sortArray(self, nums: [int]) -> [int]:
return self.minHeapSort(nums)
print(Solution().sortArray([10, 25, 6, 8, 7, 1, 20, 23, 16, 19, 17, 3, 18, 14]))