Problem E: 数量的类模板

#include<iostream>
#include<iomanip>
#include<algorithm>
using namespace std;
template<class T>
class Data
{
    private:
        T value;
    public:
        Data():value(0){}
        Data(T v):value(v){}
        void setValue(T v){ value = v;}
        T getValue(){return value;}
        bool operator>(Data<T> b){ return value > b.value;}   /*使用类模板对象时一定要显示指出模板实参*/
        bool operator<(Data<T> b){return value < b.value;}
        Data<T> operator+(const Data<T> b)
        {
            Data<T> c;
            c.value = value + b.value;
            return c;
        }
        friend ostream& operator<<(ostream &os, const Data<T> &s);       /*若写引用必须用const， 否则不能写引用&*/
        {
            os << setprecision(2) << fixed << s.value;
            return os;
        }

};

template<class T>
class GetResult
{
    public:
         static Data<T> getSum(Data<T> *arr, int num)
         {
             Data<T> sum(0);
             for(int i = 0; i < num; i++)
                sum.setValue(sum.getValue() + arr[i].getValue());
            return sum;
         }
         static Data<T> getMax(Data<T> *arr, int num)
         {
             T Max = arr[0].getValue();
             for(int i = 1; i < num; i++)
                Max = max(Max, arr[i].getValue());
            return Data<T>(Max);
         }
          static Data<T> getMin(Data<T> *arr, int num)
          {
              T Min;
              Min = arr[0].getValue();
              for(int i = 1; i < num; i++)
                Min = min(Min, arr[i].getValue());
                Data<T> m(Min);
                return m;
          }

};
//append.cc
int main()
{
    Data<int> iData[1001];
    Data<double> dData[1001];
    int cases, num;
    char ch;
    int u;
    double v;
    Data<int> a(10), b(20);
    Data<double> c(3.14), d(-4.1);
    cout<<"a + b = "<<(a + b)<<endl;
    cout<<"max(a, b) = "<<(a > b ? a : b)<<endl;
    cout<<"min(a, b) = "<<(a < b ? a : b)<<endl;
    cout<<"c + d = "<<(c + d)<<endl;
    cout<<"max(c, d) = "<<(c > d ? c : d)<<endl;
    cout<<"min(c, d) = "<<(c < d ? c : d)<<endl;
    cin>>cases;
    for (int i = 0; i < cases; i++)
    {
        cin>>ch;
        cin>>num;
        for (int j = 0; j < num; j++)
        {
            if (ch == 'i')
            {
                cin>>u;
                iData[j].setValue(u);
            }
            else if (ch == 'd')
            {
                cin>>v;
                dData[j].setValue(v);
            }
        }
        if (ch == 'i')
        {
            cout<<GetResult<int>::getMax(iData, num);
            cout<<" "<<GetResult<int>::getMin(iData, num);
            cout<<" "<<GetResult<int>::getSum(iData, num)<<endl;
        }
        else if (ch == 'd')
        {
            cout<<GetResult<double>::getMax(dData, num);
            cout<<" "<<GetResult<double>::getMin(dData, num);
            cout<<" "<<GetResult<double>::getSum(dData, num)<<endl;
        }
    }
    return 0;
}