package ugly;
public class heapSort {
//调整
public static void heapAdjust(int[] array , int index, int end){
int lchild = 2*index;
int rchild = 2*index+1;
int max = index;
if (index <= end/2){
if(lchild <= end && array[lchild] > array[max]) max = lchild;
if(rchild <= end && array[rchild] > array[max]) max = rchild;
if (max != index){
int tmp = array[max];
array[max]= array[index];
array[index] = tmp;
//避免调整之后以max为父节点的子树仍然不是堆
heapAdjust(array, max, end);
}
}
}
//建立堆
public static void buildHeap(int[] array ,int end){
//非叶节点最大序号值为end/2
for(int i = end/2; i >= 1; i--){
heapAdjust(array,i,end);
}
}
//堆排序
public static void HeapSort(int[] array ,int end){
buildHeap(array ,end);
for(int i = end; i >=1; i--){
//交换
int tmp = array[i];
array[i]= array[1];
array[1] = tmp;
//将1至i-1中最大值调整到i-1位置
heapAdjust(array,1,i-1);
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
int[] test= {-1,15,100,200,153,21,73,85,2,46,1};
HeapSort(test,10);
for (int k : test){
System.out.print(k+" ");
}
}
}
