排序算法

• 直接插入排序:
  例1: 

 int[] param1 = { 23,44,12,11,2};
int a=0;
for (int i=0;i<=3;i++)
{
 for (int j=i+1;j<=4;j++)
 {
  if (param1[i]>param1[j])
  {
   a=param1[i];
   param1[i]=param1[j];
   param1[j]=a;
  }
 }
}

例2: 

using System;
public class InsertionSorter
{
   public void Sort(int [] list)
   {
       for(int i=1;i<list.Length;++i)
       {
          int t=list[i];
          int j=i;
          while((j>0)&&(list[j-1]>t))
          {
            list[j]=list[j-1];
            --j;
          }
        list[j]=t;
       }

    }
}
public class MainClass
{
     public static void Main()
    {
     int[] iArrary=new int[]{1,5,3,6,10,55,9,2,87,12,34,75,33,47};
     InsertionSorter ii=new InsertionSorter();
     ii.Sort(iArrary);
     for(int m=0;m<=13;m++)
     Console.WriteLine("{0}",iArrary[m]); 
      }
}

---

• 如果数字比较多，你可以采用其它的算法，如二分法插入排序、冒泡排序等，一般讲算法的书中都有介绍。下面给出二分法的排序算法：(不限于5个数字）

public void BinarySort(ref int[] intArray)
{
  int n=intArray.Length;
  for(int i=1; i<n;i++)
  {
    int temp=intArray[i];
    int left=0;
    int right=i;
    while(left<right)
    {
 int mid=(left+right)/2;
 if(temp>=intArray[mid])
    left=mid+1;
 else
    right=mid;
    }
    for(int j=i; j>left;j--)
    {
 temp=intArray[j];
 intArray[j]=intArray[j-1];
 intArray[j-1]=temp;
    }
  }
}

---

• 选择排序

using System;
public class SelectionSorter
{
  // public enum comp {COMP_LESS,COMP_EQUAL,COMP_GRTR};
  private int min;
  // private int m=0;
   public void Sort(int [] list)
   {
       for(int i=0;i<list.Length-1;++i)
       {
          min=i;
          for(int j=i+1;j<list.Length;++j)
          {
            if(list[j]<list[min])
            min=j;
          }
        int t=list[min];
        list[min]=list[i];
        list[i]=t;
     //   Console.WriteLine("{0}",list[i]);
     }

    }
}
public class MainClass
{
     public static void Main()
    {
     int[] iArrary=new int[]{1,5,3,6,10,55,9,2,87,12,34,75,33,47};
     SelectionSorter ss=new SelectionSorter();
     ss.Sort(iArrary);
     for(int m=0;m<=13;m++)
     Console.WriteLine("{0}",iArrary[m]); 
 //SelectionSorter.Sort(iArrary);
     }
}
已经编译通过。

---

• 希尔排序
  希尔排序是将组分段,进行插入排序

public class ShellSorter
{
   public void Sort(int [] list)
   {
       int inc;
       for(inc=1;inc<=list.Length/9;inc=3*inc+1);
       for(;inc>0;inc/=3)
       {
           for(int i=inc+1;i<=list.Length;i+=inc)
         {
          int t=list[i-1];
          int j=i;
          while((j>inc)&&(list[j-inc-1]>t))
          {
            list[j-1]=list[j-inc-1];
            j-=inc;
          }
          list[j-1]=t;
         }
       }
    }
}
public class MainClass
{
     public static void Main()
    {
     int[] iArrary=new int[]{1,5,3,6,10,55,9,2,87,12,34,75,33,47};
     ShellSorter sh=new ShellSorter();
     sh.Sort(iArrary);
     for(int m=0;m<=13;m++)
     Console.WriteLine("{0}",iArrary[m]); 
      }
}
已经编译通过.

---

• 快速排序
  

using System;
namespace ConsoleApplication7
{
 public class Class1
 {
 public static void QuickSort (int[] intArray, int nLower, int nUpper)
    {
        if (nLower < nUpper)
        {
            int nSplit = Partition (intArray, nLower, nUpper);
            QuickSort (intArray, nLower, nSplit - 1);
            QuickSort (intArray, nSplit + 1, nUpper);
        }
    }

    static int Partition (int[] intArray, int nLower, int nUpper)
    {
        int nLeft = nLower + 1;
        int nPivot = intArray[nLower];
        int nRight = nUpper;

        int nSwap;
        while (nLeft <= nRight)
        {

            while (nLeft <= nRight && intArray[nLeft] < nPivot)
                nLeft++;

            while (nLeft <= nRight && intArray[nRight] >=nPivot )
                nRight--;
           
            if (nLeft < nRight)
            {
                nSwap = intArray[nLeft];
                intArray[nLeft] = intArray[nRight];
                intArray[nRight] = nSwap;
                nLeft++;
                nRight--;
            }
        }

        // Move pivot element
        nSwap = intArray[nLower];
        intArray[nLower] = intArray[nRight];
        intArray[nRight] = nSwap;
        return nRight;
    }
 }

 public class MainClass
 {
 static void Main(string[] args)
 {
  int[] a= new int[9] {8,6,3,5,4,9,1,2,7};

  Class1.QuickSort(a,0,a.Length-1);

  foreach (int i in a)
   Console.WriteLine(i);

  Console.ReadLine();
 }
 }
}