C#堆排序

来源：互联网发布：mac版ps字体怎么安装编辑：程序博客网时间：2024/05/19 18:47

笔试了不少校招题目主要是互联网公司题目主要为基础与海量数据悲催的百度居然死在堆排序唉上班半年基础算法很多都忘了再写一下堆排序吧

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace Caculater{    class HeapSortClass    {        public static void Main(string[] args)        {            int[] array = new int[100];            Random rdm = new Random();            for (int i = 0; i < array.Length; i++)            {                array[i] = rdm.Next(1000);            }            foreach (var i in array)            {                Console.WriteLine(i);            }            Console.ReadLine();            HeapSort(array);            foreach (var i in array)            {                Console.WriteLine(i);            }            Console.ReadLine();        }        private static void HeapSort(int[] array)        {            Build(array);            int k = 1;            foreach (var i in array)            {                Console.WriteLine(k++.ToString()+" "+i.ToString());            }            Console.ReadLine();            for (int i = array.Length; i >1 ; i--)            {                int temp = array[i-1];                array[i-1] = array[0];                array[0] = temp;                Max_Heapify(array, 1, i - 1);            }        }        private static void Build(int[] array)        {            for (int i = array.Length / 2; i >= 1; i--)            {                Max_Heapify(array, i ,array.Length);            }        }        private static void Max_Heapify(int[] array, int index,int length)        {            //length为堆的长度            int leftChild = index * 2;            int rightChild = leftChild + 1;            int largest = index;            if (leftChild <= length &&                array[leftChild-1] > array[largest-1])            {                largest = leftChild;            }            if (rightChild <= length &&                array[rightChild-1] > array[largest-1])            {                largest = rightChild;            }            if (largest != index)            {                int temp = array[index-1];                array[index-1] = array[largest-1];                array[largest-1] = temp;                Max_Heapify(array, largest,length);            }        }    }}