排序python堆和列表 [英] sorting python heaps and lists

问题描述

我正在尝试解决以下问题

I'm trying to do the following problem

目的:quicheSort算法的实现(不到位)， 它首先使用quickSort，使用3位中值枢轴，直到它 达到以int(math.log(N，2))为边界的递归限制. 在此，N是要排序的初始列表的长度. 一旦达到该深度限制，它将切换为使用heapSort而不是 快速排序.

purpose: Implementation of the quicheSort algorithm (not in place), It first uses quickSort, using the median-of-3 pivot, until it reaches a recursion limit bounded by int(math.log(N,2)). Here, N is the length of the initial list to sort. Once it reaches that depth limit, it switches to using heapSort instead of quicksort.

import heapSort            # heapSort
import qsPivotMedian3
from math import*                 # log2 (for quicksort depth limit)
import testSorts            # run (for individual test run)

def quicheSortRec(lst, limit):
    """
    A non in-place, depth limited quickSort, using median-of-3 pivot.
    Once the limit drops to 0, it uses heapSort instead.
    """
    if len(lst) == 0:
        return lst()
    elif limit > 0:
        quickSort(lst)
    else:
        heapSort(lst)

def quicheSort(lst):
    """
    The main routine called to do the sort.  It should call the
    recursive routine with the correct values in order to perform
    the sort
    """
    if len(lst)== 0:
        return list()
    else:
        limit = float(log(len(lst),[2]))
        return quicheSortRec(lst,limit)

if __name__ == "__main__":
    testSorts.run('quicheSort')

此代码的问题是我的局限性.我应该将限制设置为int(log(N，[2])).但是，python一直告诉我需要一个浮点数.因此，当我将int更改为float时，仍然会告诉我需要float.

The problem i'm having with this code is my limits. I'm supposed to set the limit as int(log(N,[2])). However, python keeps telling me a float is needed. So when I change int to float it still keeps telling me a float is needed.

回溯-

le "/Users/sps329/Desktop/quicheSort.py", line 44, in <module>
    testSorts.run('quicheSort')
  File "/Users/sps329/Desktop/testSorts.py", line 105, in run
    performSort(sortType, data, N)
  File "/Users/sps329/Desktop/testSorts.py", line 71, in performSort
    result = sortType.function(dataSet.data)
  File "/Users/sps329/Desktop/quicheSort.py", line 40, in quicheSort
    limit = float(log(len(lst),[2]))
TypeError: a float is required

推荐答案

        limit = float(log(len(lst),[2]))

[2]是一个1元素的列表.为什么要列出1个元素的清单?您只想在这里2.我认为也许这应该是地板的数学符号，但是2楼也没有太大意义.

[2] is a 1-element list. Why are you making a 1-element list? You just want 2 here. I'd think maybe that was supposed to be mathematical notation for a floor, but flooring 2 doesn't make much sense either.

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