用Java实现几种常见的排序算法

插入排序：

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;
/**
 * @author treeroot
 * @since 2006-2-2
 * @version 1.0
 */
public class InsertSort implements SortUtil.Sort{

    /* (non-Javadoc)
     * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
     */
    public void sort(int[] data) {
        int temp;
        for(int i=1;i             for(int j=i;(j>0)&&(data[j]                 SortUtil.swap(data,j,j-1);
            }
        }       
    }

}

冒泡排序：

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
 * @author treeroot
 * @since 2006-2-2
 * @version 1.0
 */
public class BubbleSort implements SortUtil.Sort{

    /* (non-Javadoc)
     * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
     */
    public void sort(int[] data) {
        int temp;
        for(int i=0;i             for(int j=data.length-1;j>i;j--){
                if(data[j]                     SortUtil.swap(data,j,j-1);
                }
            }
        }
    }

}

选择排序：

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
 * @author treeroot
 * @since 2006-2-2
 * @version 1.0
 */
public class SelectionSort implements SortUtil.Sort {

    /*
     * (non-Javadoc)
     *
     * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
     */
    public void sort(int[] data) {
        int temp;
        for (int i = 0; i < data.length; i++) {
            int lowIndex = i;
            for (int j = data.length - 1; j > i; j--) {
                if (data[j] < data[lowIndex]) {
                    lowIndex = j;
                }
            }
            SortUtil.swap(data,i,lowIndex);
        }
    }

}

Shell排序：

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
 * @author treeroot
 * @since 2006-2-2
 * @version 1.0
 */
public class ShellSort implements SortUtil.Sort{

    /* (non-Javadoc)
     * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
     */
    public void sort(int[] data) {
        for(int i=data.length/2;i>2;i/=2){
            for(int j=0;j                 insertSort(data,j,i);
            }
        }
        insertSort(data,0,1);
    }

    /**
     * @param data
     * @param j
     * @param i
     */
    private void insertSort(int[] data, int start, int inc) {
        int temp;
        for(int i=start+inc;i             for(int j=i;(j>=inc)&&(data[j]                 SortUtil.swap(data,j,j-inc);
            }
        }
    }

}

快速排序： package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; /**  * @author treeroot  * @since 2006-2-2  * @version 1.0  */ public class QuickSort implements SortUtil.Sort{     /* (non-Javadoc)      * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])      */     public void sort(int[] data) {         quickSort(data,0,data.length-1);            }     private void quickSort(int[] data,int i,int j){         int pivotIndex=(i+j)/2;         //swap         SortUtil.swap(data,pivotIndex,j);                  int k=partition(data,i-1,j,data[j]);         SortUtil.swap(data,k,j);         if((k-i)>1) quickSort(data,i,k-1);         if((j-k)>1) quickSort(data,k+1,j);              }     /**      * @param data      * @param i      * @param j      * @return      */     private int partition(int[] data, int l, int r,int pivot) {         do{            while(data[++l]            while((r!=0)&&data[--r]>pivot);            SortUtil.swap(data,l,r);         }         while(l         SortUtil.swap(data,l,r);                return l;     } } 改进后的快速排序： package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; /**  * @author treeroot  * @since 2006-2-2  * @version 1.0  */ public class ImprovedQuickSort implements SortUtil.Sort {     private static int MAX_STACK_SIZE=4096;     private static int THRESHOLD=10;     /* (non-Javadoc)      * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])      */     public void sort(int[] data) {         int[] stack=new int[MAX_STACK_SIZE];                  int top=-1;         int pivot;         int pivotIndex,l,r;                 stack[++top]=0;         stack[++top]=data.length-1;                 while(top>0){             int j=stack[top--];             int i=stack[top--];                         pivotIndex=(i+j)/2;             pivot=data[pivotIndex];                         SortUtil.swap(data,pivotIndex,j);                         //partition             l=i-1;             r=j;             do{                 while(data[++l]                 while((r!=0)&&(data[--r]>pivot));                 SortUtil.swap(data,l,r);             }             while(l             SortUtil.swap(data,l,r);             SortUtil.swap(data,l,j);                         if((l-i)>THRESHOLD){                 stack[++top]=i;                 stack[++top]=l-1;             }             if((j-l)>THRESHOLD){                 stack[++top]=l+1;                 stack[++top]=j;             }                     }         //new InsertSort().sort(data);         insertSort(data);     }     /**      * @param data      */     private void insertSort(int[] data) {         int temp;         for(int i=1;i             for(int j=i;(j>0)&&(data[j]                 SortUtil.swap(data,j,j-1);             }         }           } }