C#实现所有经典排序算法

1、选择排序
选择排序
class SelectionSorter    
{    
    private int min;    
    public void Sort(int[] arr)    
    {    
        for (int i = 0; i < arr.Length - 1; ++i)    
        {    
            min = i;    
            for (int j = i + 1; j < arr.Length; ++j)    
            {    
                if (arr[j] < arr[min])    
                    min = j;    
            }    
            int t = arr[min];    
            arr[min] = arr[i];    
            arr[i] = t;    
        }    
    }    
}
2、冒泡排序
冒泡排序
class EbullitionSorter    
{    
    public void Sort(int[] arr)    
    {    
        int i, j, temp;    
        bool done = false;    
        j = 1;    
        while ((j < arr.Length) && (!done))//判断长度    
        {    
            done = true;    
            for (i = 0; i < arr.Length - j; i++)    
            {    
                if (arr[i] > arr[i + 1])    
                {    
                    done = false;    
                    temp = arr[i];    
                    arr[i] = arr[i + 1];//交换数据    
                    arr[i + 1] = temp;    
                }    
            }    
            j++;    
        }    
    }      
}
3、快速排序
快速排序
class QuickSorter    
{    
    private void swap(ref int l, ref int r)    
    {    
        int temp;    
        temp = l;    
        l = r;    
        r = temp;    
    }    
    public void Sort(int[] list, int low, int high)    
    {    
        int pivot;//存储分支点    
        int l, r;    
        int mid;    
        if (high <= low)    
            return;    
        else if (high == low + 1)    
        {    
            if (list[low] > list[high])    
                swap(ref list[low], ref list[high]);    
            return;    
        }    
        mid = (low + high) >> 1;    
        pivot = list[mid];    
        swap(ref list[low], ref list[mid]);    
        l = low + 1;    
        r = high;    
        do   
        {    
        while (l <= r && list[l] < pivot)    
            l++;    
        while (list[r] >= pivot)    
            r--;    
            if (l < r)    
                swap(ref list[l], ref list[r]);    
        } while (l < r);    
        list[low] = list[r];    
        list[r] = pivot;    
        if (low + 1 < r)    
            Sort(list, low, r - 1);    
        if (r + 1 < high)    
            Sort(list, r + 1, high);    
    }      
}   
4、插入排序
插入排序 
public class InsertionSorter    
{    
    public void Sort(int[] arr)    
    {    
        for (int i = 1; i < arr.Length; i++)    
        {    
            int t = arr[i];    
            int j = i;    
            while ((j > 0) && (arr[j - 1] > t))    
            {    
                arr[j] = arr[j - 1];//交换顺序    
                --j;    
            }    
            arr[j] = t;    
        }    
    }     
}   
5、希尔排序
希尔排序
public class ShellSorter    
{    
    public void Sort(int[] arr)    
    {    
        int inc;    
        for (inc = 1; inc <= arr.Length / 9; inc = 3 * inc + 1) ;    
        for (; inc > 0; inc /= 3)    
        {    
            for (int i = inc + 1; i <= arr.Length; i += inc)    
            {    
                int t = arr[i - 1];    
                int j = i;    
                while ((j > inc) && (arr[j - inc - 1] > t))    
                {    
                    arr[j - 1] = arr[j - inc - 1];//交换数据    
                    j -= inc;    
                }    
                arr[j - 1] = t;    
            }    
        }    
    }   
}  
6、归并排序
归并排序
        /// <summary>
        /// 归并排序之归：归并排序入口
        /// </summary>
        /// <param name="data">无序的数组</param>
        /// <returns>有序数组</returns>
        /// <author>Lihua(www.zivsoft.com)</author>
        int[] Sort(int[] data)
        {
            //取数组中间下标
            int middle = data.Length / 2;
            //初始化临时数组let,right，并定义result作为最终有序数组
            int[] left = new int[middle], right = new int[middle], result = new int[data.Length];
            if (data.Length % 2 != 0)//若数组元素奇数个，重新初始化右临时数组
            {
                right = new int[middle + 1];
            }
            if (data.Length <= 1)//只剩下1 or 0个元数，返回，不排序
            {
                return data;
            }
            int i = 0, j = 0;
            foreach (int x in data)//开始排序
            {
                if (i < middle)//填充左数组
                {
                    left[i] = x;
                    i++;
                }
                else//填充右数组
                {
                    right[j] = x;
                    j++;
                }
            }
            left = Sort(left);//递归左数组
            right = Sort(right);//递归右数组
            result = Merge(left, right);//开始排序
            //this.Write(result);//输出排序,测试用(lihua debug)
            return result;
        }
        /// <summary>
        /// 归并排序之并:排序在这一步
        /// </summary>
        /// <param name="a">左数组</param>
        /// <param name="b">右数组</param>
        /// <returns>合并左右数组排序后返回</returns>
        int[] Merge(int[] a, int[] b)
        {
            //定义结果数组，用来存储最终结果
            int[] result = new int[a.Length + b.Length];
            int i = 0, j = 0, k = 0;
            while (i < a.Length && j < b.Length)
            {
                if (a[i] < b[j])//左数组中元素小于右数组中元素
                {
                    result[k++] = a[i++];//将小的那个放到结果数组
                }
                else//左数组中元素大于右数组中元素
                {
                    result[k++] = b[j++];//将小的那个放到结果数组
                }
            }
            while (i < a.Length)//这里其实是还有左元素，但没有右元素
            {
                result[k++] = a[i++];
            }
            while (j < b.Length)//右右元素，无左元素
            {
                result[k++] = b[j++];
            }
            return result;//返回结果数组
        }
注：此算法由周利华提供（http://www.cnblogs.com/architect/archive/2009/05/06/1450489.html 
）
7、基数排序
基数排序
        //基数排序
        public int[] RadixSort(int[] ArrayToSort, int digit)
        {   
            //low to high digit
            for (int k = 1; k <= digit; k++)
            {       
                //temp array to store the sort result inside digit
                int[] tmpArray = new int[ArrayToSort.Length]; 
                //temp array for countingsort 
                int[] tmpCountingSortArray = new int[10]{0,0,0,0,0,0,0,0,0,0};        
                //CountingSort        
                for (int i = 0; i < ArrayToSort.Length; i++)        
                {           
                    //split the specified digit from the element 
                    int tmpSplitDigit = ArrayToSort[i]/(int)Math.Pow(10,k-1) - (ArrayToSort[i]/(int)Math.Pow(10,k))*10; 
                    tmpCountingSortArray[tmpSplitDigit] += 1; 
                }         
                for (int m = 1; m < 10; m++)      
                {            
                    tmpCountingSortArray[m] += tmpCountingSortArray[m - 1];        
                }        
                //output the value to result      
                for (int n = ArrayToSort.Length - 1; n >= 0; n--)       
                {           
                    int tmpSplitDigit = ArrayToSort[n] / (int)Math.Pow(10,k - 1) - (ArrayToSort[n]/(int)Math.Pow(10,k)) * 10;           
                    tmpArray[tmpCountingSortArray[tmpSplitDigit]-1] = ArrayToSort[n];            
                    tmpCountingSortArray[tmpSplitDigit] -= 1;       
                }        
                //copy the digit-inside sort result to source array       
                for (int p = 0; p < ArrayToSort.Length; p++)       
                {           
                    ArrayToSort[p] = tmpArray[p];       
                }   
            }    
            return ArrayToSort;
        }
8、计数排序
计数排序
//计数排序
        /// <summary>
        /// counting sort
        /// </summary>
        /// <param name="arrayA">input array</param>
        /// <param name="arrange">the value arrange in input array</param>
        /// <returns></returns>
        public int[] CountingSort(int[] arrayA, int arrange)
        {    
            //array to store the sorted result, 
            //size is the same with input array. 
            int[] arrayResult = new int[arrayA.Length];    
            //array to store the direct value in sorting process   
            //include index 0;    
            //size is arrange+1;    
            int[] arrayTemp = new int[arrange+1];    
            //clear up the temp array    
            for(int i = 0; i <= arrange; i++)    
            {        
                arrayTemp[i] = 0; 
            }    
            //now temp array stores the count of value equal 
            for(int j = 0; j < arrayA.Length; j++)   
            {       
                arrayTemp[arrayA[j]] += 1;   
            }    
            //now temp array stores the count of value lower and equal 
            for(int k = 1; k <= arrange; k++)   
            {       
                arrayTemp[k] += arrayTemp[k - 1]; 
            }     
            //output the value to result    
            for (int m = arrayA.Length-1; m >= 0; m--)   
            {        
                arrayResult[arrayTemp[arrayA[m]] - 1] = arrayA[m];    
                arrayTemp[arrayA[m]] -= 1; 
            }    
            return arrayResult;
        }

9、小根堆排序
小根堆排序
/// <summary>
        /// 小根堆排序
        /// </summary>
        /// <param name="dblArray"></param>
        /// <param name="StartIndex"></param>
        /// <returns></returns>
        private void HeapSort(ref double[] dblArray)
        {
            for (int i = dblArray.Length - 1; i >= 0; i--)
            {
                if (2 * i + 1 < dblArray.Length)
                {
                    int MinChildrenIndex = 2 * i + 1;
                    //比较左子树和右子树，记录最小值的Index
                    if (2 * i + 2 < dblArray.Length)
                    {
                        if (dblArray[2 * i + 1] > dblArray[2 * i + 2])
                            MinChildrenIndex = 2 * i + 2;
                    }
                    if (dblArray[i] > dblArray[MinChildrenIndex])
                    {

                        ExchageValue(ref dblArray[i], ref dblArray[MinChildrenIndex]);
                        NodeSort(ref dblArray, MinChildrenIndex);
                    }
                }
            }
        }
        /// <summary>
        /// 节点排序
        /// </summary>
        /// <param name="dblArray"></param>
        /// <param name="StartIndex"></param>
        private void NodeSort(ref double[] dblArray, int StartIndex)
        {
            while (2 * StartIndex + 1 < dblArray.Length)
            {
                int MinChildrenIndex = 2 * StartIndex + 1;
                if (2 * StartIndex + 2 < dblArray.Length)
                {
                    if (dblArray[2 * StartIndex + 1] > dblArray[2 * StartIndex + 2])
                    {
                        MinChildrenIndex = 2 * StartIndex + 2;
                    }
                }
                if (dblArray[StartIndex] > dblArray[MinChildrenIndex])
                {
                    ExchageValue(ref dblArray[StartIndex], ref dblArray[MinChildrenIndex]);
                    StartIndex = MinChildrenIndex;
                }
            }
        }
        /// <summary>
        /// 交换值
        /// </summary>
        /// <param name="A"></param>
        /// <param name="B"></param>
        private void ExchageValue(ref double A, ref double B)
        {
            double Temp = A;
            A = B;
            B = Temp;
        }

 选择排序

选择排序是从冒泡排序演化而来的，每一轮比较得出最小的那个值，然后依次和每轮比较的第一个值进行交换。 
目的：按从小到大排序。 
方法：假设存在数组：72, 54, 59, 30, 31, 78, 2, 77, 82, 72 
第一轮依次比较相邻两个元素，将最小的一个元素的索引和值记录下来，然后和第一个元素进行交换。 
如上面的数组中，首先比较的是72,54，记录比较小的索引是54的索引1。接着比较54和59，比较小的索引还是1。直到最后得到最小的索引是2的索引6，然后索引6和0互相交换。 
第二轮比较的时候是最小的一个元素和索引1进行交换。第三轮、第四轮以此类推。

class Program
{
    static List<int> list = new List<int>() { 72, 54, 59, 30, 31, 78, 2, 77, 82, 72 };
         
    static void Main(string[] args)
    {
        Choice();
        PrintList();
    }
 
    static void Choice()
    {
        int temp = 0;
        int minIndex = 0;
        for (int i = 0; i < list.Count; i++)
        {
            minIndex = i;
            for (int j = i; j < list.Count; j++)
            {
                //注意这里比较的是list[minIndex]
                if (list[j] < list[minIndex])
                {
                    minIndex = j;
                }
            }
            temp = list[minIndex];
            list[minIndex] = list[i];
            list[i] = temp;
            PrintList();
        }
 
    }
 
    private static void PrintList()
    {
        foreach (var item in list)
        {
            Console.Write(string.Format("{0} ", item));
        }
        Console.WriteLine();
    }
 
}