python 二元堆積

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• BinaryHeap() 建立一個新的，空的二元堆積。
• insert(k) 向堆添加一個新項。
• findMin() 返回具有最小索引值的項，並將項留在堆中。
• delMin() 返回具有最小索引值的項，從堆中刪除該項。
• 如果堆是空的，isEmpty() 返回 true，否則返回 false。
• size() 返回堆中的項數。
• buildHeap(list) 從鍵列表構建一個新的堆。

from pythonds.trees.binheap import BinHeapbh = BinHeap()bh.insert(5)bh.insert(7)bh.insert(3)bh.insert(11)print(bh.delMin())print(bh.delMin())print(bh.delMin())print(bh.delMin())

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 - 1bh = BinHeap()bh.buildHeap([9,5,6,2,3])print(bh.delMin())print(bh.delMin())print(bh.delMin())print(bh.delMin())print(bh.delMin())

 

python 二元堆積