数据结构中的堆

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

namespace Heap
{
    /// <summary>
    /// 堆排序实现
    /// </summary>
    class HeapSort
    {
        public static void Sort<T>(T[] originArr) where T : IComparable
        {
            //首先建堆
            BuildMaxHeap<T>(originArr);

            //在一个堆上在进行排序
            RealSort<T>(originArr);
        }

       
        private static void RealSort<T>(T[] originArr) where T : IComparable
        {
            for (int i = 0; i < originArr.Length-1; i++)
            {
                Swap<T>(originArr , 0, originArr.Length - (i+1));
                MaxHeapIFY<T>(originArr, originArr.Length - (i + 1), 0);
            }
        }

        /// <summary>
        /// 1.首先是需要清楚 GetMaxObjInHeap方法的作用，是在一个堆上插入一个值，并保证插入后堆的性质不变
        /// 2.堆其实是满足完全二叉树的性质的，也就是 叶子节点 = （总结点+1）/2  或者 总结点 / 2
        /// 3.把每个叶子节点看做一个独立的最大堆，自底而上构建最大堆
        /// </summary>
        private static void BuildMaxHeap<T>(T[] originArr) where T : IComparable
        {
            int len = originArr.Length / 2;
            for (int i = len; i >= 0 ; i--)
            {
                MaxHeapIFY<T>(originArr,originArr.Length, i);
            }
        }


        /// <summary>
        /// 堆操作中核心方法，并维护最大堆的性质
        /// 假设originList是一个最大堆，实现在堆固定位置插入元素，并同时保证最大堆的性质
        /// </summary>
        private static void MaxHeapIFY<T>(T[] originList, int heapSie, int pos) where T : IComparable
        {
            int len = heapSie;
            int largest = 0;
            int cLeft = pos * 2;
            int cRight = pos * 2 + 1;
            while (cLeft < len || cRight < len)
            {
                largest = cLeft;
                if (cRight < len && originList[cLeft].CompareTo(originList[cRight]) < 0)
                {
                    largest = cRight;
                }
                if (originList[pos].CompareTo(originList[largest]) >= 0)
                {
                    break;
                }
                else
                {
                    Swap<T>(originList, pos, largest);
                    pos = largest;
                    cLeft = pos * 2;
                    cRight = pos * 2 + 1;
                }

            }
        }

        /// <summary>
        /// 数组中两个元素交换
        /// </summary>
        private static void Swap<T>(T[] originList, int posFirst, int posSec) where T : IComparable
        {
            T temp = originList[posFirst];
            originList[posFirst] = originList[posSec];
            originList[posSec] = temp;
        }

        public static void PrintArr<T>(T[] arr)
        {
            for (int i = 0; i < arr.Length; i++)
            {
                Console.Write(arr[i] + " , ");
            }
            Console.WriteLine("");
            Console.WriteLine("==================");

        }
    }
}