How can you choose a line that fulfills all the conditions?

How do we know the number of common values between two lines from two different tables? using csharp.

table1.row[1]={5,6,3,4,1}

 table2.row[3]={6,4,16,18,7,'2'}

// table2.row[3][5] is char mean number of duplicate value must be to return true (i make it char because i dont want program use this
value whenthey do comparison)//

in this two table the funcion need to return true
because we have two duplicate number and its the same value given by user in table2.row[3][5]

>Solution :

There are many ways to find duplicates.

Here’s one that doe not use anything C# specific.

var a = new [] {5,2,3,4,1};
var b = new [] {2,4,16,18,'2'};


List<object> commonElements =  new(); // You can also just count 'duplicates'
for(int i = 0; i < a.Length; i++)
    for(int j = 0; j < b.Length; j++)    
        if(b[j] == a[i]) 
        {   
            commonElements.Add(a[i]); 
            break;
        }
Console.WriteLine(string.Join(",",commonElements));

This prints 2,4.

Later you can

if(commonElements.Count == user_input)
{
    ...
}

BTW. Please note that '2' and 2 would not be considered the same.