我的虚析构函数不会在抽象类中调用

我的程序不会调用基类的虚析构函数。我发现了这个方法http://www.programmerinterview.com/index.php/c-cplusplus/virtual-destructors/所以我不知道怎么了。可以找人帮忙吗

#include <iostream>
#include <vector>
using namespace std;
class Number{
    private:
        int *arr;
        int n;
    public:
        Number(int *a, int i):
            arr(a),n(i){}
        virtual vector<int> operator()()=0;
        int* getArr(){return arr;}
        int getValueAt(int i){return arr[i];}
        int size(){return n;}
        virtual ~Number(){ delete [] arr;
            cout<<"In Number destructor"<<endl;
        }
};
class Odd: public Number{
    public:
        Odd(int *ar,int n1):
            Number(ar,n1){}
        vector<int> operator()();
        ~Odd(){}
};
class Even: public Number{
    public:
        Even(int *ar,int n1):
            Number(ar,n1){}
        vector<int> operator()();
        ~Even(){}
};
/*
 *      operator()()
 *  -input
 *      none
 *  -description
 *      returns a vector with all the
 *      odd numbers. This will be sent in
 *      as a function parameter to a
 *      higher order function
 *  -output
 *      vector<int> with odd values
 */
vector<int> Odd::operator ()()
{
    vector<int> temp;
    for(int i=0; i<Number::size(); i++){
        if(Number::getArr()[i]%2==1)
            temp.push_back(Number::getValueAt(i));
    }
    return temp;
}
/*
 *      operator()()
 *  -input
 *      none
 *  -description
 *      returns a vector with all the
 *      even numbers. This will be sent in
 *      as a function parameter to a
 *      higher order function
 *  -output
 *      vector<int> with even values
 */
vector<int> Even::operator ()()
{
    vector<int> temp;
    for(int i=0; i<Number::size(); i++){
        if(Number::getArr()[i]%2==0)
            temp.push_back(Number::getValueAt(i));
    }
    return temp;
}
/*
 *      filter()
 *  input:
 *      Takes a number object
 *  description:
 *      filter is a higher order function and
 *      it will return a vector with depending
 *      how the operator() is defined
 *  output:
 *      vector<int>
 */
vector<int> filter(Number *a)
{
    return (*a)();
}
/*
 *      addAll()
 *  input:
 *      Takes a number object
 *  description:
 *      addAll is a higher order function and
 *      it will return sum of a vector returned
 *      from a filtering process that depends on
 *      the definition of operator() being invoked
 *  output:
 *      vector<int>
 */
int addAll(Number *a)
{
    vector<int> temp=(*a)();
    int sum=0;
    for(unsigned int i=0; i< temp.size();i++){
        sum+=temp[i];
    }
    return sum;
}
/*
 *  This program was written to explore functional programming
 *  concepts in c++. One such concept is high order functions
 *
 *  I created an abstract Number class which contains an int
 *  array and size of the array. I also made two derived classes
 *  that define the virtual operator() function. I pass a 
 *  polymorphic pointer variable to the higher order functions
 *  and they call the overloaded operator()() which is dynamically
 *  binded during runtime and the correct vector and sum should be 
 *  returned by the functions
 *  
 *  One bug that I have is that the base destructor is not being called
 *  warning!! this function will cause memory leaks
 */
int main()
{
    int array[]={1,2,3,4,5,6,7,8,9,10};
    Number *even=new Even(array,sizeof(array)/sizeof(array[0]));
    Number *odd=new Odd(array,sizeof(array)/sizeof(array[0]));
    vector<int> temp=filter(even);
    cout<<"The even numbers in array are: ";
    for(unsigned int i=0; i<temp.size();i++){
        cout<<temp[i]<<" ";
    }
    cout<<endl;
    cout<<"The sum of all the even numbers is "
        <<addAll(even)<<endl;
    temp=filter(odd);
    cout<<"The odd numbers in array are: ";
    for(unsigned int i=0; i<temp.size();i++){
        cout<<temp[i]<<" ";
    }
    cout<<endl;
    cout<<"The sum of all the odd numbers is "
        <<addAll(odd)<<endl;
    delete even;
    delete odd;
}