Get maximum closest number from int list

December 13, 2021

I have number list like below and I should check a condition to get most suitable match.

List<int> numbers= new List<int>();
numbers.Add(1000);
numbers.Add(3000);
numbers.Add(5500);
numbers.Add(7000);

If I send a value to check it should check like below examples

Scenario 1:
If I send a value less than or equal 1000 to check, it should return 1000

Scenario 2:
If I send a value between 1001 – 3000 to check, it should return 3000

Scenario 3:
If I send a value between 3001 – 5500 to check, it should return 5500

Scenario 4:
If I send a value between 5501 – 7000 to check, it should return 7000

Scenario 5:
If I send a value above 7000 to check, it should return nothing.

Can I do this with Linq? or what is the most efficient way to do this?

Update: the numbers in maxCheckPoint is dynamic and it can be any values. So we cannot hard coded and check

>Solution :

You can do this with LINQ:

int input = 1000;
int? result = numbers
    .OrderBy(n => n) // get the numbers in ascending order
    .SkipWhile(n => n < input) // skip until the remaining set >= input
    .Cast<int?>() // cast to nullable int
    .FirstOrDefault(); // take the first or default entry (if no items remain, it will be null)