在C＃中置换算法 [英] Permutation algorithms in C#

问题描述

我在努力奋斗着这个算法我需要写。我使用C＃。

I'm struggling with this algorithm I need to write. I'm using C#.

说我有一个名单，其中，袋＆GT; 和我有一个名单，其中，午餐＆GT; 。 我需要写一个算法，将枚举午餐的所有排列在所有的包装袋。

Say I have a List<Bag> and I have a List<Lunch>. I need to write an algorithm which will enumerate all permutations of lunches in all bags.

举例来说，假设有3个午餐，2袋：

For example, say there are 3 lunches and 2 bags:

// Permutation 1
Bag 1, Lunch 1
Bag 2, Lunch 1

// Permutation 2
Bag 1, Lunch 1
Bag 2, Lunch 2

// Permutation 3
Bag 1, Lunch 1
Bag 2, Lunch 3

// Permutation 4
Bag 1, Lunch 2
Bag 2, Lunch 1

// Permutation 5
Bag 1, Lunch 2
Bag 2, Lunch 2

// Permutation 6
Bag 1, Lunch 2
Bag 2, Lunch 3

// Permutation 7
Bag 1, Lunch 3
Bag 2, Lunch 1

// Permutation 8
Bag 1, Lunch 3
Bag 2, Lunch 2

// Permutation 9
Bag 1, Lunch 3
Bag 2, Lunch 3

这两个排列袋1午餐1和包2午餐2 和袋1午餐2袋2午餐1 是不同的，因为包包有不同的容量，因此他们都需要加以列举。

The two permutations Bag 1 Lunch 1 and Bag 2 Lunch 2 and Bag 1 Lunch 2 and Bag 2 Lunch 1 are different because the bags have different capacities, hence they would both need to be enumerated.

的袋和午餐的数量可以是任何数量。

The number of bags and lunches can be any number.

我已经创建了一个名为 BagLunch ，其中包含一个包和午餐对。我在上面已经给出的例子清单将被存储在一个名单，其中，BagLunch＆GT;

I have created a class called BagLunch which contains a bag and lunch pair. The example list I've given above would be stored in a List<BagLunch>.

感谢你。

推荐答案

使用交叉联接在LINQ：

Use a cross join in LINQ:

var qry = from bag in bags
          from lunch in lunches
          select new BagLunch 
          { Bag=bag, Lunch=lunch};
var baglunches = qry.ToList();

编辑：
你要修改的SELECT子句来处理你的 BagLunch 类的结构。

You'll want to modify the select clause to handle the structure of your BagLunch class.

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