using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace QueueTest
{
    public struct pqItem {
        public int priority;
        public string name;
    }
    /// <summary>
    /// 源自Queue的優(yōu)先隊(duì)列
    /// </summary>
    class PQueue:Queue
    {
        public PQueue() {


        }
        /// <summary>
        /// 重寫出隊(duì)
        /// </summary>
        /// <returns></returns>
        public override object Dequeue()
        {
            object[] items;//數(shù)組
            int min;//數(shù)字越小優(yōu)先級(jí)越大
            items = this.ToArray();//隊(duì)列元素復(fù)制到數(shù)組
            min = ((pqItem)items[0]).priority;//默認(rèn)數(shù)組索引為0的優(yōu)先級(jí)最大
            //
            for (int i = 0; i <= items.GetUpperBound(0); i++)            
                if (((pqItem)items[i]).priority<min)
                {
                    min = ((pqItem)items[i]).priority;//優(yōu)先級(jí)重新設(shè)置
                }

                this.Clear();//從隊(duì)列中移除所有對(duì)象
                int x2;
            //對(duì)數(shù)組循環(huán)遍歷
                for (x2 = 0; x2 < items.GetUpperBound(0); x2++)
               //如果數(shù)組中找到優(yōu)先級(jí)最高的（且名字不為空） 就進(jìn)隊(duì) 
                    if (((pqItem)items[x2]).priority ==min&&((pqItem)items[x2]).name!="")                    
                        this.Enqueue(items[x2]); //進(jìn)隊(duì) 
            Console.WriteLine(this.Count); //值為1                                      
            return base.Dequeue();//先進(jìn)先出
        }

        static void Main() {
            PQueue erwait = new PQueue();//創(chuàng)建一個(gè)隊(duì)列
            pqItem[] erPatient = new pqItem[3];//創(chuàng)建pqItem的數(shù)組

            pqItem nextPatient;//下一個(gè)
            erPatient[0].name = "Joe Smith";
            erPatient[0].priority = 1;

            erPatient[1].name = "Mary Smith";
            erPatient[1].priority = 0;

            erPatient[2].name = "Sam Smith";
            erPatient[2].priority = 3;

            for (int i = 0; i <= erPatient.GetUpperBound(0); i++)
            {
                erwait.Enqueue(erPatient[i]);
            }
            Console.WriteLine(erwait.Count);//值為3 
            nextPatient =(pqItem)erwait.Dequeue();
            Console.WriteLine(erwait.Count);//值為0 
            Console.WriteLine(nextPatient.name);
            Console.Read();

        }
    }
}