#include<iostream.h> class sample{ int n; public: sample(int i){n=i; } void add( ){s+=n;} static int s; void dis( ){ cout<<s<<endl; } }; int sample ::s=0 void main() { sample a(2),b(5),c(8); a. add( ); b. add( ); c. dis( ); }

抱歉，但是我的回答中不能包含实际的代码。在你提供的示例中，有一些语法错误。首先，`#include<iostream.h>`应该改为`#include<iostream>`。其次，在C++中，`main()`函数的返回类型应该是`int`而不是`void`。此外，`sample::add()`函数中的`s`应该是`n`，因为`s`没有定义。修正后的代码如下所示：

#include<iostream>

class sample {
    int n;
public:
    sample(int i) { n = i; }
    void add() { n += n; }
    static int s;
    void dis() {
        std::cout << n << std::endl;
    }
};

int sample::s = 0;

int main() {
    sample a(2), b(5), c(8);
    a.add();
    b.add();
    c.dis();

    return 0;
}

请注意，这只是一个修正的示例，可能还有其他错误或需要进一步完善的地方。如果你有其他问题或需要更多帮助，请随时提问。

相关问题

class Question: def __init__(self, stem, options, answer): self.stem = stem self.options = options self.answer = answerclass QuestionBank: def __init__(self): self.questions = [] def add_question(self, question): self.questions.append(question) def remove_question(self, question): self.questions.remove(question) def get_random_questions(self, num): return random.sample(self.questions, num)class Paper: def __init__(self, questions): self.questions = questions self.answers = {} def answer_question(self, question, answer): self.answers[question] = answer def get_score(self): score = 0 for question, answer in self.answers.items(): if answer == question.answer: score += 1 return scoreclass Grader: def __init__(self, paper): self.paper = paper def grade(self): return self.paper.get_score()# Example usagequestion1 = Question("What is the capital of France?", ["Paris", "London", "Berlin", "Madrid"], "Paris")question2 = Question("What is the largest planet in the solar system?", ["Mercury", "Venus", "Earth", "Jupiter"], "Jupiter")question3 = Question("What is the highest mountain in the world?", ["K2", "Mount Everest", "Makalu", "Cho Oyu"], "Mount Everest")question_bank = QuestionBank()question_bank.add_question(question1)question_bank.add_question(question2)question_bank.add_question(question3)paper = Paper(question_bank.get_random_questions(2))paper.answer_question(question1, "Paris")paper.answer_question(question2, "Jupiter")grader = Grader(paper)score = grader.grade()print("Your score is:", score)将这个代码转为C++的

好的，以下是将 Python 代码转换为 C++ 代码的示例：

#include <iostream>
#include <vector>
#include <map>
#include <string>
#include <algorithm>
#include <random>

using namespace std;

class Question {
public:
    string stem;
    vector<string> options;
    string answer;
    Question(string s, vector<string> o, string a) {
        stem = s;
        options = o;
        answer = a;
    }
};

class QuestionBank {
public:
    vector<Question> questions;
    void add_question(Question q) {
        questions.push_back(q);
    }
    void remove_question(Question q) {
        questions.erase(remove(questions.begin(), questions.end(), q), questions.end());
    }
    vector<Question> get_random_questions(int num) {
        vector<Question> res;
        random_device rd;
        mt19937 gen(rd());
        shuffle(questions.begin(), questions.end(), gen);
        for (int i = 0; i < num; ++i) {
            res.push_back(questions[i]);
        }
        return res;
    }
};

class Paper {
public:
    vector<Question> questions;
    map<Question, string> answers;
    Paper(vector<Question> q) {
        questions = q;
    }
    void answer_question(Question q, string a) {
        answers[q] = a;
    }
    int get_score() {
        int score = 0;
        for (auto const& x : answers) {
            if (x.second == x.first.answer) {
                score++;
            }
        }
        return score;
    }
};

class Grader {
public:
    Paper paper;
    Grader(Paper p) {
        paper = p;
    }
    int grade() {
        return paper.get_score();
    }
};

int main() {
    Question question1("What is the capital of France?", {"Paris", "London", "Berlin", "Madrid"}, "Paris");
    Question question2("What is the largest planet in the solar system?", {"Mercury", "Venus", "Earth", "Jupiter"}, "Jupiter");
    Question question3("What is the highest mountain in the world?", {"K2", "Mount Everest", "Makalu", "Cho Oyu"}, "Mount Everest");
    QuestionBank question_bank;
    question_bank.add_question(question1);
    question_bank.add_question(question2);
    question_bank.add_question(question3);
    vector<Question> random_questions = question_bank.get_random_questions(2);
    Paper paper(random_questions);
    paper.answer_question(question1, "Paris");
    paper.answer_question(question2, "Jupiter");
    Grader grader(paper);
    int score = grader.grade();
    cout << "Your score is: " << score << endl;
    return 0;
}

注意，这只是一个简单的示例，实际情况下可能需要更多的代码来处理错误处理、用户输入等问题。

Write a C++ program that defines a units class that can be used to perform basic engineering problems. This expanded format creates a nice convention for building a units class in C++, which has a to

Sure, I'd be happy to help you with that! Here's a sample code for defining a units class in C++ that can be used to perform basic engineering problems:

#include <iostream>
#include <string>

using namespace std;

class Units {
    private:
        double value;
        string unit;
    public:
        Units(double v, string u) {
            value = v;
            unit = u;
        }
        double getValue() {
            return value;
        }
        string getUnit() {
            return unit;
        }
        void setValue(double v) {
            value = v;
        }
        void setUnit(string u) {
            unit = u;
        }
        void convert(string newUnit) {
            // Define conversion factors for each unit
            double factor = 1.0;
            if (unit == "m" && newUnit == "cm") {
                factor = 100.0;
            } else if (unit == "cm" && newUnit == "m") {
                factor = 0.01;
            } else if (unit == "kg" && newUnit == "g") {
                factor = 1000.0;
            } else if (unit == "g" && newUnit == "kg") {
                factor = 0.001;
            }
            // Convert value to new unit
            value *= factor;
            unit = newUnit;
        }
        Units operator+(const Units& other) {
            if (unit != other.unit) {
                cout << "Error: units are not compatible!" << endl;
                return *this;
            }
            double newValue = value + other.value;
            return Units(newValue, unit);
        }
        Units operator-(const Units& other) {
            if (unit != other.unit) {
                cout << "Error: units are not compatible!" << endl;
                return *this;
            }
            double newValue = value - other.value;
            return Units(newValue, unit);
        }
};

int main() {
    Units length(1.0, "m");
    length.convert("cm");
    cout << length.getValue() << " " << length.getUnit() << endl;
    
    Units mass1(1.0, "kg");
    Units mass2(2.0, "g");
    Units totalMass = mass1 + mass2;
    cout << totalMass.getValue() << " " << totalMass.getUnit() << endl;
    
    Units error = length + mass1;
    cout << error.getValue() << " " << error.getUnit() << endl;
    
    return 0;
}

In this code, the `Units` class has two private member variables: `value` and `unit`. The constructor initializes these variables with the provided values. The class also has various public member functions, such as `getValue()`, `getUnit()`, `setValue()`, `setUnit()`, `convert()`, and overloaded operators `+` and `-`.

The `convert()` function converts the unit of the `Units` object to a new unit, based on predefined conversion factors. The `+` and `-` operators allow the addition and subtraction of `Units` objects, respectively, as long as their units are compatible.

In the `main()` function, we create various `Units` objects and perform some basic operations with them, such as unit conversion and addition/subtraction. Note that attempting to add or subtract `Units` objects with incompatible units will result in an error message.