我将给你四分代码，分别是 poly.h, stack.h, varpool.h, interpreter.h

poly.h:

#ifndef POLY_H
#define POLY_H

#include <iostream>
#include <vector>

class Poly {
public:
    // constructors
    Poly() : coef{0} {}
    Poly(const std::vector<double>& c) : coef{c} {}

    // overloaded operators
    friend std::istream& operator>>(std::istream& is, Poly& p);
    friend std::ostream& operator<<(std::ostream& os, const Poly& p);
    friend Poly operator+(const Poly& p1, const Poly& p2);
    friend Poly operator-(const Poly& p1, const Poly& p2);
    friend Poly operator*(const Poly& p1, const Poly& p2);
    friend Poly operator/(const Poly& p1, const Poly& p2);
    friend Poly operator%(const Poly& p1, const Poly& p2);

    // member functions
    int degree() const { return coef.size() - 1; }
    double operator[](int i) const { return coef[i]; }
    double& operator[](int i) { return coef[i]; }
    double eval(double x) const;
    Poly deriv() const;

private:
    std::vector<double> coef;
};

#endif

stack.h:

#ifndef STACK_H
#define STACK_H

#include <vector>

template <typename T>
class Stack {
public:
    // constructors
    Stack() : elem{} {}
    Stack(const std::vector<T>& v) : elem{v} {}

    // member functions
    void push(const T& val) { elem.push_back(val); }
    void pop() { elem.pop_back(); }
    const T& top() const { return elem.back(); }
    bool empty() const { return elem.empty(); }

private:
    std::vector<T> elem;
};

#endif

varpool.h:

#ifndef VARPOOL_H
#define VARPOOL_H

#include <map>
#include <string>

class VarPool {
public:
    // member functions
    double get(const std::string& var_name) const;
    void set(const std::string& var_name, double val);

private:
    std::map<std::string, double> vars;
};

#endif

interpreter.h:

#ifndef INTERPRETER_H
#define INTERPRETER_H

#include <string>
#include "poly.h"
#include "varpool.h"

class Interpreter {
public:
    // constructors
    Interpreter() : pool{} {}

    // member functions
    void run_command(const std::string& cmd);
    Poly parse_poly(const std::string& cmd) const;

private:
    VarPool pool;
};

#endif