Alister Kyle Alister Kyle - 11 months ago 42
C# Question

Eliminate duplicates from array c#

I'm making a basic Deal or No Deal game, in doing so I have to pick 10 finalists from an array, at random, without repeats.

I have my structure and arrays set out like this

public struct People
public string firstname;
public string lastname;
public int age;

class Program
public static People[] People1 = new People[40];
public static People[] Finalists1 = new People[10];
public static People[] Finalist1 = new People[1];

And my finalists method set out like this

Random rand = new Random();

for (int i = 0; i < Finalists1.Length; i++)
num = rand.Next(0, People1.Length);
Finalists1[i].lastname = People1[num].lastname;
Finalists1[i].firstname = People1[num].firstname;
Finalists1[i].age = People1[num].age;

How can I eliminate duplicate entries, while maintaining 10 people in the array?

Answer Source

Since initial array doesn't contain duplicates, you can sort it in random order and pick up 10 top items:

   Finalists1 = People1
     .OrderByDescending(item => 1)   // if people have some points, bonuses etc.
     .ThenBy(item => Guid.NewGuid()) // shuffle among peers
     .Take(10)                       // Take top 10
     .ToArray();                     // materialize as an array

If people are selected to the final are not completely random (e.g. contestant can earn points, bonuses etc.) change .OrderByDescending(item => 1), e.g.

     .OrderByDescending(item => item.Bonuses)

If you don't want to use Linq, you can just draw Peoples from urn without returning:

     private static Random random = new Random();  


     List<People> urn = new List<People>(People1); 

     for (int i = 0; i < Finalists1.Length; ++i) {
       int index = random.Next(0, urn.Count);

       Finalists1[i] = urn[index];