Question

下面是我的最大堆实现。我真的可以弄清楚为什么我得到索引越界错误。我已将数组分配给self.heap

Imports Microsoft.Office.Core
Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim oXL As Excel.Application
        Dim oWB As Excel.Workbook
        Dim oSheet As Excel.Worksheet
        Dim oRng As Excel.Range

        ' Start Excel and get Application object.
        oXL = CreateObject("Excel.Application")
        oXL.Visible = True
    End Sub
End Class

错误：

class heap:
    def __init__(self):
        self.heapsize=0
        self.heap=[0]
    def builheap(self,list):
        self.heapsize =  len(list)
        self.heap=list
        for i in range(len(list)//2, 0, -1):
            self.maxheap(self.heap,i)
    def maxheap(self, list, index):
        if list[2*index]<=self.heapsize and list[2*index]>list[index]:
            largest=list[2*index]
        else:
            largest=index
        if list[2*index+1]<= self.heapsize and list[2*index+1]>list[index]:
            largest=list[2*index+1]
        if largest!=index:
            tmp = list[index]
            list[index] = list[largest]
            list[largest] = tmp
            maxheap(list,largest)

h=heap()
h.builheap([16,14,10,8,7,9,3,2,4,1])

Answer 1

您有以下代码：

    if list[2*index]<=self.heapsize and list[2*index]>list[index]:
        largest=list[2*index]
    else:
        largest=index
    if list[2*index+1]<= self.heapsize and list[2*index+1]>list[index]:

在检查索引是否超出列表边界之前，您尝试索引到列表中。此外，您要检查索引是否在边界内，而不是检查该索引的内容是否在边界内。

应该是：

    if 2*index<=self.heapsize and list[2*index]>list[index]:
        largest=list[2*index]
    else:
        largest=index
    if 2*index+1<= self.heapsize and list[2*index+1]>list[index]:

我不清楚你的根是0还是1。

如果根节点位于list[0]，则您的计算应为(2*index) + 1和(2*index)+2。您的计算假设根位于list[1]。

最大堆抛出索引越界

1 个答案: