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CSharp · Console

/Program.cs

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

public class MainClass
{
	public static void Main(string[] args)
	{
		int[] array = {10, 5, 10, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12};
		var dict = CountOccurence<int>(array);
		foreach (var pair in dict)
			Console.WriteLine("Value {0} occurred {1} times.", pair.Key, pair.Value);
		
		string[] array2 = {"10","10", "toto"};
		var dict2 = CountOccurence<string>(array2);
		foreach (var pair in dict2)
			Console.WriteLine("Value {0} occurred {1} times.", pair.Key, pair.Value);
	}

	public static IDictionary<T, int> CountOccurence<T>(IEnumerable<T> array)
	{
		return array.GroupBy(x => x).ToDictionary(x => x.Key, x => x.Count());
	}
}