How Can LINQ Efficiently Generate All Possible Puppy Combinations from Multiple Dogs?

LINQ implements Cartesian product

Suppose you have a class structure where a person owns multiple dogs and each dog has multiple puppies, and you want to find a LINQ solution to generate all possible combinations of puppies, one for each combination from each dog Choose a puppy.

The concept of Cartesian product applies here, which involves multiplying sets to produce unique combinations of elements. While SQL tables provide a simple solution for this, LINQ provides an elegant approach.

First, consider the case where the number of sets (dogs) is known at compile time. You can use a simple LINQ query:

<code>var combinations = from p1 in dog1.Puppies
                  from p2 in dog2.Puppies
                  from p3 in dog3.Puppies
                  select new {p1, p2, p3};</code>

This query will generate a series of anonymous types, each type representing a combination of puppies in each dog.

However, where the number of collections is not known at compile time, a more dynamic approach is required. You can refer to Eric Lippert's article to learn how to use LINQ to calculate the Cartesian product:

https://www.php.cn/link/f28c49d8be62973ac7716e0b87dae2f9

After getting the CartesianProduct method:

<code>var combinations = CartesianProduct(from dog in person.Dogs select dog.Puppies);</code>

This will return a sequence of sequences, where each inner sequence contains a combination of one puppy from each dog.

To summarize, whether the number of dogs is static or dynamic, you can use LINQ to generate the desired combination of puppies.

The above is the detailed content of How Can LINQ Efficiently Generate All Possible Puppy Combinations from Multiple Dogs?. For more information, please follow other related articles on the PHP Chinese website!