数据结构之顺序村村存储二叉树遍历及堆排序

//大顶堆即是二叉数的节点越低他的值越大，假如节点的位置是i，他的左叶子节点是2*i+1,右叶子节点是2*i+2
static    int[]  arr=new int[]{3,5,2,5,67,7,3,8};
    public static void frontShow(int index){
        if(arr==null||arr.length==0){
            return;
        }
        System.out.println(arr[index]);
        //查询左节点2N+1
        if(2*index+1<=arr.length-1){
            frontShow(2*index+1);
        }
        //查询右节点
        if(2*index+2<=arr.length-1){
            frontShow(2*index+2);
        }
    }
    public static void maxHeap(int[]arr, int size,int index){
        int leftIndex=2*index+1;
        int rightIndex=2*index+2;
        int max=index;
        if(leftIndex<size&&arr[max]<arr[leftIndex]){
            max=leftIndex;
        }
         if(rightIndex<size&&arr[max]<arr[rightIndex]){
            max=rightIndex;
        }
         if(max!=index){
             arr[max]=arr[max]^arr[index];
              arr[index]=arr[max]^arr[index];
              arr[max]=arr[max]^arr[index];
//重新调整前面的节点为大顶堆
             maxHeap(arr,size,max);
         }
    }
    public static void heapSort(int ... arr){
//计算最后叶子节点的父节点位置
        int index=(arr.length-1)/2;
//调整为大顶堆
        for(int i=index;i>=0;i--){
            maxHeap(arr,arr.length,i);
        }
//将降序改为升序
  /**      for(int i=arr.length-1;i>=0;i--){
            if(arr[0]>arr[i]){
                arr[0]=arr[i]^arr[0];
                 arr[i]=arr[0]^arr[i];
                 arr[0]=arr[i]^arr[0];
            }
            maxHeap(arr,i,0);
        }
**/
    }
    public static void main(String[] args) {
        frontShow(0);
        heapSort(arr);
        System.out.println(Arrays.toString(arr));
    }