二十三种设计模式：状态模式

#include <iostream>
#include <memory>
//*********************State Pattern*******************
class Work;
//抽象状态类
class State
{
public:
  virtual void WriteProgram(Work* ptrWork) = 0;
};
class ForenoonState;
//工作类
class Work
{
private:
  std::shared_ptr<State> smartState;
  double hour;
  bool finish;
public:
  Work();
  void SetHour(const double h)
  {
  hour = h;
  }
  double GetHour() const
  {
  return hour;
  }
  void SetFinish(bool bFinish)
  {
  finish = bFinish;
  }
  bool GetFinish() const
  {
  return finish;
  }
  void SetState(std::shared_ptr<State> pState)
  {
  smartState = pState;
  }
  std::shared_ptr<State> GetState() const
  {
  return smartState;
  }
  void WriteProgram()
  {
  smartState->WriteProgram(this);
  }
};
//睡眠状态
class SleepingState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  std::cout << "当前时间：" << ptrWork->GetHour() << "点 撑不住了，睡觉吧！" << std::endl;
  }
};
//下班休息状态
class RestState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  std::cout << "当前时间：" << ptrWork->GetHour() << "点 下班回家了！" << std::endl;
  }
};
//傍晚工作状态
class EveningState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  if (ptrWork->GetFinish())
  {
    ptrWork->SetState(std::make_shared<RestState>());
    ptrWork->WriteProgram();
    return;
  }
  if (ptrWork->GetHour() < 21)
  {
    std::cout << "当前时间：" << ptrWork->GetHour() << "点 加班吆，疲惫啊！" << std::endl;
  }
  else
  {//超过21点，转换到睡眠状态
    ptrWork->SetState(std::make_shared<SleepingState>());
    ptrWork->WriteProgram();
  }
  }
};
//下午工作状态
class AfternoonState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  if (ptrWork->GetHour() < 17)
  {
    std::cout << "当前时间：" << ptrWork->GetHour() << "点 下午状态还不错，继续努力！" << std::endl;
  }
  else
  {//超过17点，转换傍晚工作状态
    ptrWork->SetState(std::make_shared<EveningState>());
    ptrWork->WriteProgram();
  }
  }
};
//中午工作状态
class NoonState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  if (ptrWork->GetHour() < 13)
  {
    std::cout << "当前时间：" << ptrWork->GetHour() << "点 饿了，午饭，犯困，午休！" << std::endl;
  }
  else
  {//超过13点，转换下午工作状态
    ptrWork->SetState(std::make_shared<AfternoonState>());
    ptrWork->WriteProgram();
  }
  }
};
//上午工作状态类
class ForenoonState : public State
{
public:
  void WriteProgram(Work* ptrWork)
  {
  if (ptrWork->GetHour() < 12)
  {
    std::cout << "当前时间：" << ptrWork->GetHour() << "点 上午工作，精神百倍！" << std::endl;
  }
  else
  {//超过12点，转换中午工作状态
    ptrWork->SetState(std::make_shared<NoonState>());
    ptrWork->WriteProgram();
  }
  }
};
Work::Work() : hour(0), finish(false), smartState(std::make_shared<ForenoonState>()) {}
//************************Test**************************
int main()
{
  std::shared_ptr<Work> work = std::make_shared<Work>();
  work->SetHour(9);
  work->WriteProgram();
  work->SetHour(10);
  work->WriteProgram();
  work->SetHour(12);
  work->WriteProgram();
  work->SetHour(13);
  work->WriteProgram();
  work->SetHour(14);
  work->WriteProgram();
  work->SetHour(17);
  work->WriteProgram();
  work->SetFinish(false);
  //work->SetFinish(true);
  //work->WriteProgram();
  work->SetHour(19);
  work->WriteProgram();
  work->SetHour(22);
  work->WriteProgram();
  system("pause");
  return 0;
}

const static int NO_QUARTER = 1;
const static int HAS_QUARTER = 2;
const static int SOLD_OUT = 0;
const static int SOLD = 3;
int state = SOLD_OUT;

#include<iostream>
using namespace std;
class GumballMachine {
private:
  const static int SOLD_OUT = 0;    /* 售罄状态 */
  const static int NO_QUARTER = 1;  /* 没有25分钱状态 */
  const static int HAS_QUARTER = 2; /* 有25分钱状态 */
  const static int SOLD = 3;        /* 售出状态 */
  int state = SOLD_OUT;     /* 糖果机拆箱状态初始化为售罄状态，等待工人装入糖果 */
  int count = 0;                    /* 糖果机当前糖果数量 */
public:
  /* 构造函数初始化，装入糖果后，就需要改变糖果机当前状态为 "没有25分钱状态" */
  GumballMachine(int count) {
  this->count = count;
  if (count > 0) {
    state = NO_QUARTER; 
  }
  }
  /* 投入25分钱 */
  void insertQuarter() {
  if (state == HAS_QUARTER) {
    cout << "You can't insert another quarter" << endl;
  } else if (state == NO_QUARTER) {
    state = HAS_QUARTER; /* 只有当前状态为无25分钱状态才能执行投币操作 */
    cout << " You inserted a quarter"<<endl;
  } else if (state == SOLD_OUT) {
    cout << "You can't insert a quarter, the machine is sold out" <<endl;
  } else if (state == SOLD) {
    cout << "Please wait, we're already giving you a gumball" << endl;
  } 
  }
  /* 退回25分钱 */
  void ejectQuarter() {
  if (state == HAS_QUARTER) {
    cout<< "Quarter returned" <<endl;
    state = NO_QUARTER;
  } else if (state == NO_QUARTER) {
    cout << "You haven't inserted a quarter, we can't return quarter to you" << endl;
  } else if (state == SOLD) {
    cout << "you already turned the crank, we can't return quarter to you" << endl;
  } else if (state == SOLD_OUT) {
    cout << "You can't eject,you haven't inserted a quarter"<<endl;
  } 
  }
  /* 转动曲柄 */
  void turnCrank() {
  if (state == HAS_QUARTER) {
    cout << "You turned the crank..." << endl;
    state = SOLD;
    dispense();
  } else if (state == SOLD_OUT) {
    cout<< "You turned, but there is no gumball" <<endl;
  } else if (state == SOLD) {
    cout << "Turning twice doesn't get you another gumball!"<<endl;
  } else if (state == NO_QUARTER){
    cout<<"You turned, but there is no quarter"<<endl;
  }
  }
  /* 发放糖果 */
  void dispense(){
  if (state == HAS_QUARTER){
    cout<<"No gumball dispensed"<<endl;
  } else if (state == SOLD_OUT) {
    cout << "No gumball dispensed" << endl;
  } else if (state == SOLD) {
    cout<< "A gumball comes rolling out the slot"<<endl;
    count--;
    if (count == 0) {
    cout<<"Oops, Out of gumball! "<<endl;
    state = SOLD_OUT;
    } else {
    state = NO_QUARTER;
    }
  } else if (state == NO_QUARTER) {
    cout <<"You need to pay first"<<endl;
  }
  }
};