程序优化是用于消除程序中大量的if else这种判断语句

#include <iostream>
#include <string>

using namespace std;

class CashSuper
{
public:
        virtual double GetTotalCash(double ddwMoney) = 0;
};

class CashNormal:public CashSuper
{
public:
        virtual double GetTotalCash(double ddwMoney)
        {
                return ddwMoney;
        }
};

class CashRebate: public CashSuper
{
public:
        CashRebate(float dwRebate):m_Rebate(dwRebate)
        {

        }

        virtual double GetTotalCash(double ddwMoney)
        {
                return m_Rebate * ddwMoney;
        }

private:
        float m_Rebate;
};

class CashContext
{
public:
        CashContext()
        {
        }

        CashContext(CashSuper* pstTmpCashSuper)
        {
                m_pstCashSuper = pstTmpCashSuper;
        }

        void SetCashStrategy(CashSuper* pstTmpCashSuper)
        {
                m_pstCashSuper = pstTmpCashSuper;
        }

        double GetTotalCash(double ddwMoney)
        {
                return m_pstCashSuper->GetTotalCash(ddwMoney);
        }

private:
        CashSuper *m_pstCashSuper;
};

int main(void)
{
        CashContext* stCashContext = new CashContext(new CashNormal());

        cout<<"应付价钱为： "<< stCashContext->GetTotalCash(100)<< endl;

        stCashContext = new CashContext(new CashRebate(0.8));

        cout<<"应付价钱为： "<< stCashContext->GetTotalCash(100)<< endl;

        return 0;
}
///
[root]$ ./strategy
应付价钱为： 100
应付价钱为： 80