using System;

using System.Collections.Generic;

using System.Linq;

​

public static class Program

{

    public static void Main()

    {

        PriorityQueue<object, (char, int)> queue = new(Comparer<(char, int)>.Create((x, y) =>

        {

            int result = x.Item1.CompareTo(y.Item1);

            if (result == 0) result = x.Item2.CompareTo(y.Item2);

            return result;

        }));

​

        Random random = new(0);

        for (int i = 0; i < 100_000; i++)

        {

            char key = (char)random.Next(65, 91);

            queue.Enqueue(new object(), (key, i));

        }

        while (queue.Count > 1_000) queue.Dequeue();

​

        long mem0 = GC.GetTotalAllocatedBytes(true);

        queue.Reindex();

        long mem1 = GC.GetTotalAllocatedBytes(true);

        Console.WriteLine($"Count: {queue.Count:#,0}, Allocated: {mem1 - mem0:#,0} bytes");

​

        Console.WriteLine($"Desirable maximum: {System.Runtime.CompilerServices.Unsafe.SizeOf<(object, char)>() * queue.Count:#,0} bytes");

​

        if (queue.TryPeek(out _, out (char, int) firstKey))

            Console.WriteLine($"First key: {firstKey}");

    }

​

    public static void Reindex<TElement, TPriority>(

        this PriorityQueue<TElement, (TPriority, int)> source)

    {

        ArgumentNullException.ThrowIfNull(source);

        (TElement, (TPriority, int))[] entries = source.UnorderedItems

            .OrderBy(e => e.Priority, source.Comparer)

            .ToArray();

        source.Clear();

        for (int i = 0; i < entries.Length; i++)

            source.Enqueue(entries[i].Item1, (entries[i].Item2.Item1, i));

    }

}

​