错误C2955：'堆'：使用类模板需要模板参数列表

Question

我正在尝试为maxheap创建模板类，但我的代码中出现以下错误：

  

错误C2955：'堆'：使用类模板需要模板参数   列表

我似乎很难理解为什么会这样。这是我的代码：

Heap.h

    ifndef HEAP_H
    #define HEAP_H
    #include<vector>

    template<class T>
    class Heap{
    protected:
        std::vector<T>heap_arr;
        int tempheap_size;
        //int index;
        int left;
        int right;
        int parent;
    public:
        Heap():tempheap_size(0), left(0), right(0), parent(0){}
        void setLeft(int index){
            left = 2 * index + 1;
        }

        void setRight(int index){
            right = 2 * index + 2;
        }

        void setParent(int index){
            parent = (index - 1) / 2;
        }

        virtual void heapsort()= 0;
        virtual void insertElement(T val)= 0;
        virtual void deleteElement(T val)= 0;

        void swap(int index, int max){
            T temp = heap_arr[index];
            heap_arr[index] = heap_arr[max];
            heap_arr[max] = temp;
        }

        int findElementIndex(T val, int index){
            if (index == heap_arr.size())
                cout << "Not found\n";
            else if (heap_arr[index] == val)
                return index;
            else{
                findElementIndex(val, index + 1);
            }

        }

        void printHeap(){
            for (int i = 0; i < heap_arr.size(); i++)
                cout << heap_arr[i] << "    ";
        }

        ~Heap(){


        }

    };

 #endif

Maxheap.h

#ifndef MAXHEAP_H
#define MAXHEAP_H
#include"Heap.h"
#include<vector>

template<class T>
class Maxheap:public Heap{
public:
    Maxheap():Heap(){}
    void copyHeap(T* arr, int size){
        for (int i = 0; i < size; i++)
            heap_arr.push_back(arr[i]);

        tempheap_size = heap_arr.size();
    }

    void maxHeapify(int i){
        setLeft(i);
        setRight(i);
        int max = i;

        if (left < tempheap_size && heap_arr[left] > heap_arr[i])
            max = left;
        if (right < tempheap_size && heap_arr[right] > heap_arr[max])
            max = right;
        if (max != i){
            swap(i, max);
            maxHeapify(max);
        }

    }

    void buildMaxHeap(){
        for (int i = (heap_arr.size()) / 2 - 1; i >= 0; i--)
            maxHeapify(i);
    }

    virtual void heapSort(){
        //buildMaxHeap();
        for (int i = heap_arr.size() - 1; i >= 1; i--){
            swap(0, i);
            tempheap_size--;
            maxHeapify(0);
        }

    }

    virtual void insertElement(T val){
        heap_arr.push_back(val);
        for (int i = heap_arr.size() - 1; i > 0; i = (i - 1) / 2){
            setParent(i);
            if (heap_arr[i] > heap_arr[parent])
                swap(i, parent);
        }
        buildMaxHeap();
    }

    virtual void deleteElement(T val){
        int i = 0;
        i = findElementIndex(val, 0);
        swap(i, heap_arr.size() - 1);
        heap_arr.pop_back();
        buildMaxHeap();
        tempheap_size = heap_arr.size();
    }

    void printHeap(){
        for (int i = 0; i < heap_arr.size(); i++)
            cout << heap_arr[i] << "    ";
    }

    ~Maxheap(){

    }

};

#endif

Main.cpp的

#include<iostream>
#include"Heap.h"
#include"Maxheap.h"
using namespace std;

int main(){

    int size = 6;
    int* arr = new int[size];
    Maxheap<int> m_heap;

    cout << "Enter array\n";
    for (int i = 0; i < size; i++)
        cin >> arr[i];

    m_heap.copyHeap(arr, size);

    cout << "Heap is: \n";
    m_heap.printHeap();
    cout << "\n";

    m_heap.buildMaxHeap();

    cout << "Heap is: \n";
    m_heap.printHeap();
    cout << "\n";

    m_heap.heapSort();

    cout << "Heap is: \n";
    m_heap.printHeap();

    m_heap.insertElement(50);
    m_heap.insertElement(75);
    m_heap.insertElement(500);

    m_heap.deleteElement(25);

    cout << "Heap is: \n";
    m_heap.printHeap();

}

问题似乎在于：

template<class T>
class Maxheap:public Heap{

帮助将不胜感激。谢谢！