Random class. but inconsecutive value, like Lottery.

LotteryRandom.cs

using System.Linq;
using System.Collections.Generic;

namespace ExMath {
  
	/// <summary>
	/// Lottery random.
	/// </summary>
	public class LotteryRandom <T> {
		
		public IList<T> initialLots;
		
		Stack<int> indexes;
		
		public LotteryRandom(IList<T> initail_lots) {
			if(initail_lots.Count == 0) {
				throw new System.Exception("initial lots need more than 1");
			}
			this.initialLots = initail_lots;
			RenewIndexes();
		}
		
		void RenewIndexes() {
			var numbers = new List<int>(Enumerable.Range(0,initialLots.Count-1)).ToArray();
			var numbers2 = numbers.OrderBy(i => System.Guid.NewGuid()).ToArray();
			
			indexes = null;
			indexes = new Stack<int>(numbers2);
		}
		
		public T GetNext() {
			if(indexes.Count == 0) {
				RenewIndexes();
			}
			int i = indexes.Pop();
			return initialLots[i];
		}
	}

}

usage

LotteryRandom lottery = LotteryRandom(new List(System.Linq.Enumerable.Range(0,10)));

lottery.GetNext();
lottery.GetNext();
...
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