Java之堆排序

直接上传代码

public class Sort {
    public static void main(String[] args) {
        int[] arr = new int[]{8,7,6,5,4,3,2,1};
        HeapSort(arr, arr.length);
        for(Object obj : arr){
            System.out.println(obj);
        }
    }

    public static void AdjustDown(int[] array, int size, int root){
         int left;
         int right;
         int maxchild;
         while (true){
             left = 2*root+1;
             right = 2*root+2;
             if(left>=size){
                 return;
             }
             maxchild = left;
             if (right<size&&array[right]>array[left]){
                 maxchild = right;
             }
             if (array[root] >= array[maxchild]){
                 return;
             }
             int tmp = array[root];
             array[root] = array[maxchild];
             array[maxchild] = tmp;
             root = maxchild;
         }
    }

    public static void HeapSort(int[] array, int size){
        for(int i = (size-2)/2; i>=0; i--){
            AdjustDown(array,size, i);
        }
        for (int j = 0; j<size-1 ; j++){
            int tmp = array[0];
            array[0] = array[size-1-j];
            array[size-1-j] = tmp;
            AdjustDown(array,size-j-1, 0);
        }
    }
}