Question

我正在尝试使用buildheap进行堆排序，但是由于某种原因，我的功能无法正常工作。如果我不这样做，但HeapSort函数中的代码不在函数之外，而在函数内部时，则不起作用。我不知道如何通过创建HeapSort函数来实现

class BinHeap:
    def __init__(self):
        self.heapList = [0]
        self.currentSize = 0
    def percUp(self,i):
        while i // 2 > 0:
          if self.heapList[i] < self.heapList[i // 2]:
             tmp = self.heapList[i // 2]
             self.heapList[i // 2] = self.heapList[i]
             self.heapList[i] = tmp
          i = i // 2
    def insert(self,k):
      self.heapList.append(k)
      self.currentSize = self.currentSize + 1
      self.percUp(self.currentSize)
    def percDown(self,i):
      while (i * 2) <= self.currentSize:
          mc = self.minChild(i)
          if self.heapList[i] > self.heapList[mc]:
              tmp = self.heapList[i]
              self.heapList[i] = self.heapList[mc]
              self.heapList[mc] = tmp
          i = mc
    def minChild(self,i):
      if i * 2 + 1 > self.currentSize:
          return i * 2
      else:
          if self.heapList[i*2] < self.heapList[i*2+1]:
              return i * 2
          else:
              return i * 2 + 1
    def delMin(self):
      retval = self.heapList[1]
      self.heapList[1] = self.heapList[self.currentSize]
      self.currentSize = self.currentSize - 1
      self.heapList.pop()
      self.percDown(1)
      return retval
    def buildHeap(self,alist):
      i = len(alist) // 2
      self.currentSize = len(alist)
      self.heapList = [0] + alist[:]
      while (i > 0):
          self.percDown(i)
          i = i - 1

    def HeapSort(alist): 
        bh = BinHeap()
        bh.buildHeap(alist)
        while bh.currentSize != 0:
            print(bh.delMin())

te = [9,5,6,2,3]                    
print(HeapSort(te))

Answer 1

您有答案，只是无法返回？

def HeapSort(alist):
    result = []
    bh = BinHeap()
    bh.buildHeap(alist)
    while bh.currentSize != 0:
        result.append(bh.delMin())
    return result

如果您希望它返回列表，只需构建一个列表并返回即可。

在使用buildheap时尝试HeapSort

1 个答案: