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表示为平衡二进制堆的优先级队列：queue [n]的两个子级是queue [2 * n + 1]和queue [2 *(n + 1)]。 优先级队列由比较器或元素的自然顺序进行排序。

这是使用PriorityQueue的最大堆和最小堆的工作代码-

class HeapDemo {

private final static int HEAP_SIZE = 10; //size of heap

//INNER CLASS

static class maxHeapComparator implements Comparator {

@Override

public int compare (Integer x, Integer y) {

return y-x; //reverse order

}

}

public static void main(String[] args) {

PriorityQueue minHeap = new PriorityQueue<>(HeapDemo.HEAP_SIZE);

PriorityQueue maxHeap = new PriorityQueue<>(HeapDemo.HEAP_SIZE, new maxHeapComparator());

for(int i=1; i<=HeapDemo.HEAP_SIZE; ++i){

int data = new Random().nextInt(100) +1; //number between 0 to 100

minHeap.add(data);

maxHeap.add(data);

}

System.out.print("\nMIN Heap : ");

Iterator iter = minHeap.iterator();

while(iter.hasNext()){

System.out.print(iter.next() + " ");

}

System.out.print("\nMAX Heap : ");

iter = maxHeap.iterator();

while(iter.hasNext()) {

System.out.print(iter.next() + " ");

}

}

}

样本输出/输出：

MIN Heap : 20 32 37 41 53 91 41 98 47 86

MAX Heap : 98 91 41 53 86 20 37 41 32 47