How to find the same digits in numbers?

Question

C++ / C#

I have numbers: 23 and 11 (the numbers are different and should return true), 45 and 94 (one of the numbers is the same, should return false). how to do it?

I only managed to do with linq:

Console.WriteLine(a.ToString().All(_=> !b.ToString().Contains(_)));

Answer 1

https://dotnetfiddle.net/tAobxz
ps but of course it's better like this
https://dotnetfiddle.net/7pgNVE