package kpp.sort;
/**
* 快速排序
* 一般选取首元素为枢轴元素,保存至pivot,确定头尾指针left,right,
* 先对整个数组元素进行排序,此时枢轴元素两侧元素有序,再分别对枢轴元素两侧的两个数组执行排序
* 排序规则
* 1.right指针从右向左遍历,如果比当前枢轴元素pivot小,则将data[right]赋给data[left]
* 2.left指针从左向右遍历,如果比当前枢轴元素pivot大,则将data[left]赋给data[right]
* 3.当left和right指针走到一起时,比如index,则将pivot赋给data[index]
*
* @author kpp
*
*/
public class QuickSort {
public static void main(String[] args) {
// TODO Auto-generated method stub
int array[] = {49,38,65,97,176,213,227,49,78,34,12,164,11,18,1};
quickSort(array, 0, array.length - 1);
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]+" ");
}
}
private static int quickSort(int data[],int left,int right){
int pivot;
if(left < right){
pivot = sort(data,left,right);
System.out.println(pivot);
quickSort(data,left,pivot-1);
quickSort(data,pivot+1,right);
}
return 0;
}
private static int sort(int data[],int left,int right){
int pivot = data[left];
while(left < right){
while(left < right&&data[right] >= pivot){
right--;
}
data[left]=data[right];
while(left < right&&data[left] <= pivot){
left++;
}
data[right]=data[left];
}
//left==right时,证明祠堂排序完毕,将枢轴元素赋给data[left]
data[left] = pivot;
return left;
}
}