我必须使用最少的元素间比较数，在python中对5个元素的列表进行排序的执行计划建模.除此之外，复杂性无关紧要.
I have to model the execution plan of sorting a list of 5 elements, in python, using the minimum number of comparisons between elements. Other than that, the complexity is irrelevant.
结果是成对的列表，表示在另一时间对列表进行排序所需的比较.
The result is a list of pairs representing the comparisons needed to sort the list at another time.
我知道有一种算法可以在7个比较中做到这一点(在元素之间，总是，而不是在复杂度方面)，但是我找不到可读的(对我来说)版本.
I know there's an algorithm that does this in 7 comparisons (between elements, always, not complexity-wise), but I can't find a readable (for me) version.
如何对7个比较中的5个元素进行排序，并为排序建立一个执行计划"?
How can I sort the 5 elements in 7 comparisons, and build an "execution plan" for the sort?
PD:不是作业.
推荐答案这符合您对5 elements in 7 comparisons排序的描述:
This fits your description of sorting 5 elements in 7 comparisons:
import random n=5 ran=[int(n*random.random()) for i in xrange(n)] print ran def selection_sort(li): l=li[:] sl=[] i=1 while len(l): lowest=l[0] for x in l: if x<lowest: lowest=x sl.append(lowest) l.remove(lowest) print i i+=1 return sl print selection_sort(ran)这使用了选择排序，它不是最有效的方法，但使用的比较很少.
This uses a Selection Sort which is NOT the most efficient, but does use very few comparisons.
这可以简化为:
def ss(li): l=li[:] sl=[] while len(l): sl.append(l.pop(l.index(min(l)))) return sl在任何一种情况下，都将打印以下内容:
In either case, prints something like this:
[0, 2, 1, 1, 4] 1 2 3 4 5 [0, 1, 1, 2, 4]Perl有一个名为 Algorithm :: Networksort 的可爱模块，可让您玩用这些. Knuth引用了Bose-Nelson算法的几个比较器，您可以在此处看到它.
Perl has a lovely module called Algorithm::Networksort that allows you to play with these. The Bose-Nelson algorithm is cited by Knuth for few comparators and you can see it here.
修改
插入排序也可以很好地工作:
def InsertionSort(l): """ sorts l in place using an insertion sort """ for j in range(1, len(l)): key = l[j] i = j - 1 while (i >=0) and (l[i] > key): l[i+1] = l[i] i = i - 1 l[i+1] = key