【设计模式】策略模式

来源：爱编程的大丙

策略模式定义一系列的算法，并且将每种算法都放入到独立的类中，在实际操作中使这些算法对象可以互相替换。

#include<iostream>
#include<string>
using namespace std;class AbstractStrategy {
public:virtual void fight(bool isfar = false) = 0;virtual ~AbstractStrategy() {}
};class YiDang :public AbstractStrategy {
public:void fight(bool isfar = false)override {cout << "***现在是使用的一档：";if (isfar) {cout << "橡胶机关枪" << endl;}else {cout << "橡胶·攻城炮" << endl;}}
};class ErDang :public AbstractStrategy {
public:void fight(bool isfar = false)override {cout << "***切换二档：";if (isfar) {cout << "橡胶Jet火箭" << endl;}else {cout <<"橡胶Jet·铳乱打" << endl;}}
};class SanDang :public AbstractStrategy {
public:void fight(bool isfar = false)override {cout << "***切换三档：";if (isfar) {cout << "橡胶巨人回旋弹" << endl;}else {cout << "橡胶巨人战斧"  << endl;}}
};class SiDang :public AbstractStrategy {
public:void fight(bool isfar = false)override {cout << "***切换四档：";if (isfar) {cout << "橡胶狮子火箭炮" << endl;}else {cout << "橡胶犀牛榴弹炮" << endl;}}
};class WuDang :public AbstractStrategy {
public:void fight(bool isfar = false)override {cout << "*** 切换成五挡: 变成尼卡形态可以把物体变成橡胶, 并任意改变物体的形态对其进行攻击!!!"<<endl;}
};
//难度级别
enum class Level :char {Easy,Normal,Hard,Experts,Professional};
//路飞
class Luffy {
public:void fight(Level level, bool isfar = false) {if (m_strategy) {delete m_strategy;m_strategy = nullptr;}switch (level){case Level::Easy:m_strategy = new YiDang;break;case Level::Normal:m_strategy = new ErDang;break;case Level::Hard:m_strategy = new SanDang;break;case Level::Experts:m_strategy = new SiDang;break;case Level::Professional:m_strategy = new WuDang;break;default:break;}m_strategy->fight(isfar);}~Luffy() {delete m_strategy;}private:AbstractStrategy* m_strategy = nullptr;
};int main() {Luffy* luffy = new Luffy;cout << "--- 在香波地群岛遇到了海军士兵: " << endl;luffy->fight(Level::Easy);cout << "--- 在魔谷镇遇到了贝拉米: " << endl;luffy->fight(Level::Normal);cout << "--- 在司法岛遇到了罗布·路奇: " << endl;luffy->fight(Level::Hard);cout << "--- 在德雷斯罗萨遇到了多弗朗明哥: " << endl;luffy->fight(Level::Experts);cout << "--- 在鬼岛遇到了凯多: " << endl;luffy->fight(Level::Professional);delete luffy;return 0;
}