2017-07-17 09:55:13       个评论    来源：Youda的博客
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快速排序的Java实现

原理：

```/**
* 快速排序
* @author Youda
*
*/
public class Quick {

public static void sort(Comparable[] s,int lo, int hi){

if(lo >= hi){
return;
}

int j = partition(s,lo,hi); //拆分
sort(s,lo,j-1); //排序左半部分
sort(s,j+1,hi); //排序右半部分

}

/**
* 拆分，左半部分小于v ,右半部分大于v v = s[lo];
* @param s
* @param lo
* @param hi
* @return
*/
public static int partition(Comparable[] s, int lo, int hi){
int i = lo;
int j = hi +1;
Comparable v = s[lo];

while(true){
while(less(s[++i],v)){
if(i == hi){
break;
}
}

while(less(v,s[--j])){
if(j == lo){
break;
}
}

if(i >= j){
break;
}
exchange(s, i, j);

}
exchange(s, lo, j);
return j;
}

//比较x是否小于y
public static boolean less(Comparable x, Comparable y){
return x.compareTo(y)<0;
}

//交换 x,y
public static void exchange(Comparable[] src,int x,int y){
Comparable z = src[x]; src[x] = src[y]; src[y] = z;
}

public static void main(String[] args) {

//测试数据
String[] src = {"a","x","z","i","y","o","l","q","b","d","z","s","c"};
Integer[] src1 = {100,99,70,98,99,101,3,6,676,45,25,77,80,1,0,46,28,11111,56666,22,6,8,29};

System.out.println("===========原数组==========");
for(String str:src){
System.out.print(str+",");
}

sort(src, 0, src.length-1);//排序

System.out.println();
System.out.println("==========排序后==========");
for(String str:src){
System.out.print(str+",");
}

System.out.println();
System.out.println("==========原数组=========");
for(int i=0;i<src1.length;i++){ system.out.print(src1[i]+",");="" }="" sort(src1,="" 0,="" src1.length-1);="" system.out.println();="" system.out.println("="=========排序后==========&quot;);" for(int="" i="0;i排序结果：

```