独特的排列生成器? [英] Unique permutation generator?

问题描述

问题:我有一些数字列表，例如[1,1,2].我需要生成唯一的排列.排列为[1,1,2],[1,1,2],[1,2,1],[1,2,1],[2,1,1],[2,1,1].我只需要生成唯一的排列，即[1,1,2],[1,2,1],[2,1,1].

The problem: I have some list of numbers, like [1,1,2]. I need to generate the unique permutations. The permutations are [1,1,2],[1,1,2],[1,2,1],[1,2,1],[2,1,1],[2,1,1]. I need to only generate the unique permutations, i.e., [1,1,2],[1,2,1],[2,1,1].

我的尝试:我的第一个尝试是保留一组现有排列，并为itertools.permutations生成器创建一个过滤器，该过滤器将使用该过滤器过滤出重复项.但是，出于效率考虑，我宁愿不首先生成这些排列.即使只列出一小部分12个数字，其中只有1％是唯一的.

My attempt: My first attempt was to keep a set of existing permutations, and create a filter for the itertools.permutations generator that would use the set to filter out duplicates. However, for efficiency reasons, I would rather not generate those permutations in the first place. Even for a small list of 12 numbers, only 1% of them are unique.

我开始似乎无法完全理解:我可以在列表中创建唯一值的排列，即[1,2]，将其余数字放在所有不同的位置

I have the start of an idea that I can't seem to figure out all the way: I could create permutations of the unique values in my list, i.e., [1,2], put the remaining numbers in all the different places.

感谢您的帮助，要明确地说，我不想过滤掉重复的排列，我只想首先生成唯一的排列.

Thanks for any help, and to be clear, I do not want to filter out duplicate permutations, I want to generate only unique permutations in the first place.

推荐答案

我从我的笔记本电脑无法使用set(permutations(seq))方法执行长度为11的输入序列，但是使用此方法可以！

My laptop can't do length-11 input sequences with the set(permutations(seq)) method, but with this method it can!

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