分数四则运算 C++代码 以及控制流程图

以下是一个完整的分数四则运算的 C++ 代码，并附有控制流程图：

#include <iostream>
#include <cmath>

using namespace std;

class Fraction {
private:
    int numerator;  // 分子
    int denominator;  // 分母

public:
    Fraction(int n, int d) {
        numerator = n;
        denominator = d;
    }

    void reduce() {
        int gcd = __gcd(numerator, denominator);
        numerator /= gcd;
        denominator /= gcd;
    }

    Fraction operator+(const Fraction& other) {
        int n = numerator * other.denominator + other.numerator * denominator;
        int d = denominator * other.denominator;
        Fraction result(n, d);
        result.reduce();
        return result;
    }

    Fraction operator-(const Fraction& other) {
        int n = numerator * other.denominator - other.numerator * denominator;
        int d = denominator * other.denominator;
        Fraction result(n, d);
        result.reduce();
        return result;
    }

    Fraction operator*(const Fraction& other) {
        int n = numerator * other.numerator;
        int d = denominator * other.denominator;
        Fraction result(n, d);
        result.reduce();
        return result;
    }

    Fraction operator/(const Fraction& other) {
        int n = numerator * other.denominator;
        int d = denominator * other.numerator;
        Fraction result(n, d);
        result.reduce();
        return result;
    }

    bool operator<(const Fraction& other) {
        return numerator * other.denominator < other.numerator * denominator;
    }

    bool operator>(const Fraction& other) {
        return numerator * other.denominator > other.numerator * denominator;
    }

    void print() {
        cout << numerator << "/" << denominator << endl;
    }
};

int main() {
    int n1, d1, n2, d2;
    char op;

    cout << "请输入第一个分数的分子和分母：";
    cin >> n1 >> d1;
    Fraction a(n1, d1);

    cout << "请输入第二个分数的分子和分母：";
    cin >> n2 >> d2;
    Fraction b(n2, d2);

    cout << "请选择运算符（+、-、*、/）：";
    cin >> op;

    Fraction c;
    switch (op) {
        case '+':
            c = a + b;
            break;
        case '-':
            c = a - b;
            break;
        case '*':
            c = a * b;
            break;
        case '/':
            c = a / b;
            break;
        default:
            cout << "运算符不合法！" << endl;
            return 0;
    }

    cout << "运算结果为：";
    c.print();

    if (a < b) {
        cout << "第一个分数小于第二个分数。" << endl;
    } else if (a > b) {
        cout << "第一个分数大于第二个分数。" << endl;
    } else {
        cout << "两个分数相等。" << endl;
    }

    return 0;
}

控制流程图如下：


用户需要依次输入两个分数的分子和分母，然后选择要进行的运算符。程序根据用户的选择，使用对应的操作符对两个分数进行计算，得到结果并输出。同时，程序还会比较两个分数的大小，并输出比较结果。如果用户输入的运算符不合法，程序会输出错误信息并退出。