八大排序算法之堆排序

package java面试宝典;
import java.util.Arrays;
public class 堆排序 {
	public static void main(String[] args) {
		int[] a={6,9,3,5,7,1,8,0,2,4};
		System.out.println(Arrays.toString(a));
		heapSort(a);
		System.out.println(Arrays.toString(a));
	}
	public static void heapSort(int[] a){
		for (int i = a.length/2-1; i >=0; i--) {
			adjHeap(a, i,a.length);
		}
		for (int i = a.length-1; i >0; i--) {
			swap(a, 0, i);
			adjHeap(a, 0,i);
		}
	}
	public static void swap(int[] a,int i,int j){
		int temp=a[i];
		a[i]=a[j];
		a[j]=temp;
	}
	public static void adjHeap(int[] a,int i,int len){
		for (int k = 2*i+1; k < len; k=2*i+1) {
			if(k+1<len&&a[k]<a[k+1]){
				k++;
			}
			if(a[i]<a[k]){
				int temp=a[i];
				a[i]=a[k];
				a[k]=temp;
				i=k;
			}else{
				break;
			}
		}
	}
}