堆排序

package sort;

public class CheapSort {
    
    public static final int MAX=10;
    
    public static void main(String[] args){
        int []a={0,16,7,3,20,17,8};
        int len=a.length;
            
        buildHeap(a,len-1);
        
        for(int i=1; i<len; i++)
            System.out.print(a[i]+",");
        
        sort(a,len-1);
        System.out.println();
        
        for(int i=1; i<len; i++)
            System.out.print(a[i]+",");
        
    }
    
    public static void sort(int[] a,int size){
        
        int n=size-1;
        
        if(n==1)
            return;
        swap(a,1,size);

        adjustHeap(a,1,n);
        sort(a,n);
    }
    
    public static void swap(int[] a,int i,int j){
        int temp;
        temp=a[i];
        a[i]=a[j];
        a[j]=temp;
    }
    
    public static void buildHeap(int[] a,int size){
        
        for(int i=size/2; i>0; i--)
            adjustHeap(a,i,size);
    }

    private static void adjustHeap(int[] a, int i, int size) {
        // TODO Auto-generated method stub
    
        int lchild=i*2;
        int rchild=i*2+1;
        int max=i;
        
        if(lchild<size && a[lchild]>a[max])
            max=lchild;
        if(rchild<size && a[rchild]>a[max])
            max=rchild;
        if(max!=i)
        {
            swap(a,i,max);
            adjustHeap(a,max,size);
        }

    }
}