how to search a List<list<int>> with another List<int> in c#-CodePudding

I have the following lists of list.

List<List<int>> paths = new List<List<int>>();
paths.Add(new List<int>() { 0,1 });
paths.Add(new List<int>() { 0, 2 });
paths.Add(new List<int>() { 0, 4 });
paths.Add(new List<int>() { 1, 2 });
paths.Add(new List<int>() { 0, 3 });

and I have another List of int like this

List<int> ends = new List<int>(){3,4};

Now I need to filter records where any number in the inner list in paths contains any numbers from the ends list, which for this example would be the following records.

{0,3}
{0,4}

I tried something like this

paths.Where(x => x.Where(y => ends.Contains(y))).ToList();

CodePudding user response：

 paths.Where(x => x.Any(z => ends.Contains(z)))

CodePudding user response：

Use Any to solve your problem:

var res = paths.Where(list => list.Any(item => ends.Any(end => end==item))).ToList();

or shorter

var res = paths.Where(list => list.Any(item => ends.Contains(item))).ToList();

Result:

CodePudding user response：

LINQ syntax would be an expressive alternative for this:

var matches = (from p in paths
               from e in ends
               where p.Contains(e)
               select p).Distinct();

CodePudding user response：

class Program
{
    private static void Main(string[] args)
    {
        var paths = new List<List<int>>
        {
            new List<int>() { 0, 1 },
            new List<int>() { 0, 2 },
            new List<int>() { 0, 4 },
            new List<int>() { 1, 2 },
            new List<int>() { 0, 3 }
        };

        var ends = new List<int>(){3,4};
        var results = paths.Where(x => ends.Any(x.Contains));
        
        // display results
        foreach(var result in results)
            Console.WriteLine(JsonSerializer.Serialize(result));
    }
}

//[0,4]
//[0,3]