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]
SortUtil.swap(data,l,r);
}
while(l
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]
SortUtil.swap(data,l,r);
}
while(l
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
}
}
}
}