using System;

// Реализация АТД Очередь
public class Queue<T>
{
    private T[] elements;
    private int front, rear, size, capacity;

    public Queue(int capacity)
    {
        this.capacity = capacity;
        elements = new T[capacity];
        front = size = 0;
        rear = capacity - 1;
    }

    public void Enqueue(T item)
    {
        if (size == capacity)
            throw new Exception("Queue is full");
        rear = (rear + 1) % capacity;
        elements[rear] = item;
        size++;
    }

    public T Dequeue()
    {
        if (size == 0)
            throw new Exception("Queue is empty");
        T item = elements[front];
        front = (front + 1) % capacity;
        size--;
        return item;
    }

    // Реализация СД Массив
    public static void SelectionSort(int[] array)
    {
        for (int i = 0; i < array.Length - 1; i++)
        {
            int minIndex = i;
            for (int j = i + 1; j < array.Length; j++)
            {
                if (array[j] < array[minIndex])
                {
                    minIndex = j;
                }
            }
            if (minIndex != i)
            {
                int temp = array[i];
                array[i] = array[minIndex];
                array[minIndex] = temp;
            }
        }
    }

    // Быстрая сортировка
    public static void QuickSort(int[] array, int left, int right)
    {
        if (left < right)
        {
            int pivot = Partition(array, left, right);
            QuickSort(array, left, pivot - 1);
            QuickSort(array, pivot + 1, right);
        }
    }

    private static int Partition(int[] array, int left, int right)
    {
        int pivot = array[right];
        int i = left - 1;
        for (int j = left; j < right; j++)
        {
            if (array[j] < pivot)
            {
                i++;
                int temp = array[i];
                array[i] = array[j];
                array[j] = temp;
            }
        }
        int temp1 = array[i + 1];
        array[i + 1] = array[right];
        array[right] = temp1;
        return i + 1;
    }

    public static void Main()
    {
        int[] array = { 64, 34, 25, 12, 22, 11, 90 };

        // Сортировка выбором
        Console.WriteLine("Before selection sort:");
        foreach (var item in array) Console.Write(item + " ");
        SelectionSort(array);
        Console.WriteLine("\n\nAfter selection sort:");
        foreach (var item in array) Console.Write(item + " ");

        // Быстрая сортировка
        Console.WriteLine("\n\nBefore quick sort:");
        foreach (var item in array) Console.Write(item + " ");
        QuickSort(array, 0, array.Length - 1);
        Console.WriteLine("\n\nAfter quick sort:");
        foreach (var item in array) Console.Write(item + " ");

        // Использование Очереди
        Queue<int> queue = new Queue<int>(5);
        queue.Enqueue(10);
        queue.Enqueue(20);
        queue.Dequeue();
    }
}