我正在尝试使用数组实现最小堆。我面临的问题是，当我从技术上轮询一个元素时，它应该从堆中返回一个最小的元素。
但是使用我写的代码，它并没有给出最小的元素
输出：
插入堆：1 3 2 6 4 5
轮询值：1
轮询后的新堆：3 5 2 6 4
轮询值：3
轮询后的新堆：4 5 2 6
轮询值：4
轮询后的新堆：5 6 2
所需输出：轮询时应给出最小值
主类代码：

public class HeapApp {

    public static void main(String[] args) {
            Heap hg = new Heap(6);
            hg.insert(6);
            hg.insert(5);
            hg.insert(4);
            hg.insert(3);
            hg.insert(2);
            hg.insert(1);
            System.out.print("inserted heap: ");
            hg.print();
            System.out.println();
            System.out.println("Polledvlaue : "+hg.poll());
            System.out.print("New Heap after poll : ");hg.print();
            System.out.println();
            System.out.println("Polled value :"+hg.poll());
            System.out.print("New Heap after poll : "); hg.print();
            System.out.println();
            System.out.println("Polled value :"+hg.poll());

            System.out.print("New Heap after poll : ");hg.print();
            }

}

堆类：

public class Heap {
    private int heapSize;
    private int arr[];
    Heap(int capacity){
        heapSize = 0;
        arr = new int[capacity];
    }

    public boolean isFull() {
        return heapSize == arr.length;
    }

    public boolean isEmpty() {
        return heapSize == 0;
    }

    public void insert(int element) {
        if(isFull()) {
            throw new RuntimeException("Heap is full");
        }
        arr[heapSize] = element;
        heapSize++;
        heapifyUp();

    }

    private void heapifyUp() {

        int index = heapSize-1;

        while(index > 0 ) {
            if( arr[(index-1)/2] > arr[index]) {
            int temp = arr[index];
            arr[index] = arr[(index-1)/2];
            arr[(index-1)/2] = temp;
            index = (index-1)/2;    
            }else {
                break;
            }
        }

    }

    public int poll() {
        if(isEmpty())
            throw new RuntimeException("Heap is empty");
        int ans = arr[0];
        arr[0] = arr[heapSize-1];
        heapSize--;
        heapifyDown();
        return ans;
    }

    private void heapifyDown() {
        int index = 0;
        int left = 2*index+1;
        while(left < heapSize) {
            int min = left ; int right = ++left;
            if(right < heapSize) {
                if(arr[left] > arr[right]) {
                    min++;
                }
            }
            if(arr[index] > arr[min]) {
                int temp = arr[min];
                arr[min] = arr[index];
                arr[index] = temp;
            }
            index = min;
            left = 2*index+1;
        }
    }

    public void print() {
        for(int i = 0 ; i < heapSize ; i++) {
            System.out.print(arr[i]+" ");
        }
        System.out.println();
    }

}