/*
 * Strategy.cpp
 *	策略模式
 *  Created on: 2016年3月14日 下午4:30:31
 *      Author: Wayne 13186259527@163.com
 */

#include <iostream>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
using namespace std;

class CashSuper {
public:
	virtual double acceptCash(double money) {
		return 0;
	}
};
//原价类
class CashNormal: public CashSuper {
public:
	virtual double acceptCash(double money) {
		return money;
	}
};
//打折类
class CashRebate: public CashSuper {
private:
	double moneyRebate;
public:
	CashRebate(double mR) {
		moneyRebate = mR;
	}
	virtual double acceptCash(double money) {
		return money * moneyRebate;
	}
};
//返现类
class CashReturn: public CashSuper {
private:
	double moneyCondition;
	double moneyReturn;
public:
	CashReturn(double mC, double mR) {
		moneyCondition = mC;
		moneyReturn = mR;
	}
	virtual double acceptCash(double money) {
		double reult = money;
		if (money >= moneyCondition) {
			reult = money - floor((money / moneyCondition)) * moneyReturn;
		}
		return reult;
	}
};
//具体的操作类
class Context {
private:
	CashSuper *cs;
public:
	Context(CashSuper * CS) {
		cs = CS;
	}
	double GetResult(double money) {
		return cs->acceptCash(money);
	}
};

int main(void) {
	Context *c = NULL;
	int choice;
	double money;
	double result;
	//printf("hello\n");
	cout << "请输入金额（>0）：\n";
	cin >> money;
	cout << "请输入打折方式：" << endl;
	cout << "1------原价" << endl;
	cout << "2------打八折" << endl;
	cout << "3------满300返100" << endl;
	while (true) {
		cin >> choice;
		if (choice == 1 || choice == 2 || choice == 3) {
			break;
		}
		cout << "输入有误，请输入1、2和3中任一数字" << endl;
	}
	switch (choice) {
	case 1:
		c = new Context(new CashNormal());
		break;
	case 2:
		c = new Context(new CashRebate(0.8));
		break;
	case 3:
		c = new Context(new CashReturn(300, 100));
		break;
	}
	result = c->GetResult(money);
	cout << "result = " << result << endl;
	return 0;
}