c++ 使用结构体实现有理数库

问题描述

使用结构体设计实现有理数库。使用整数表示有理数的分子与分母，完成有理数的加减乘除与简化运算。

代码实现

刚学习C++，对知识掌握不全面，有问题欢迎各位纠正。

1. 头文件 rational_number.h

struct rational_number
{
    int numerator;   //分子
    int denominator; //分母
};
rational_number create();
void show_rational_number(rational_number x);
rational_number add(rational_number x, rational_number y);
rational_number sub(rational_number x, rational_number y);
rational_number multi(rational_number x, rational_number y);
rational_number div(rational_number x, rational_number y);
rational_number simplify(rational_number x);

2. 库内容实现：rational_number.cpp

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include "rational_number.h"

using namespace std;

rational_number create();
void show_rational_number(rational_number x);
int get_gcd(int x, int y);
rational_number simplify(rational_number x);
rational_number add(rational_number x, rational_number y);
rational_number sub(rational_number x, rational_number y);
rational_number multi(rational_number x, rational_number y);
rational_number div(rational_number x, rational_number y);

/*输入有理数*/
rational_number create()
{
    rational_number x;
    cout << "Input number for numerator and denominator, like '1 2' means 1/2: ";
    cin >> x.numerator >> x.denominator;
    if (x.denominator == 0)
    {
        cout << "denominator value error, it cannot be 0!" << endl;
        exit(1);
    }
    //如果分母为负数，统一将符号给分子，分母设置为正数
    if (x.denominator < 0)
    {
        x.numerator *= (-1);
        x.denominator *= (-1);
    }
    show_rational_number(x);
    cout << endl;
    return x;
}

void show_rational_number(rational_number x)
{
    cout << x.numerator << "/" << x.denominator;
}

/*欧式算法求最大公约数*/
int get_gcd(int x, int y)
{
    x = x < 0 ? (-1 * x) : x;
    y = y < 0 ? (-1 * y) : y;
    unsigned int r = x % y;
    while (r != 0)
    {
        x = y;
        y = r;
        r = x % y;
    }
    return y;
}

/*简化有理数*/
rational_number simplify(rational_number x)
{
    rational_number r;
    int t = get_gcd(x.numerator, x.denominator);
    if (t)
    {
        r.numerator = x.numerator / t;
        r.denominator = x.denominator / t;
    }
    return r;
}

rational_number add(rational_number x, rational_number y)
{
    rational_number result;
    x = simplify(x);
    y = simplify(y);
    result.numerator = x.numerator * y.denominator + y.numerator * x.denominator;
    result.denominator = x.denominator * y.denominator;
    result = simplify(result);
    return result;
}
rational_number sub(rational_number x, rational_number y)
{
    rational_number result;
    x = simplify(x);
    y = simplify(y);
    result.numerator = x.numerator * y.denominator - y.numerator * x.denominator;
    result.denominator = x.denominator * y.denominator;
    result = simplify(result);
    return result;
}
rational_number multi(rational_number x, rational_number y)
{
    rational_number result;
    x = simplify(x);
    y = simplify(y);
    result.numerator = x.numerator * y.numerator;
    result.denominator = x.denominator * y.denominator;
    result = simplify(result);
    return result;
}
rational_number div(rational_number x, rational_number y)
{
    rational_number result;
    x = simplify(x);
    y = simplify(y);
    result.numerator = x.numerator * y.denominator;
    result.denominator = x.denominator * y.numerator;
    result = simplify(result);
    return result;
}

3. 主调函数：main.cpp

#include <iostream>
#include "rational_number.h"

using namespace std;

int main()
{
    rational_number x, y;
    x = create();
    y = create();
    cout << "x: ";
    show_rational_number(x);
    cout << " after simplify: ";
    show_rational_number(simplify(x));
    cout << endl;

    cout << "y: ";
    show_rational_number(y);
    cout << " after simplify: ";
    show_rational_number(simplify(y));
    cout << endl;

    cout << "x + y = ";
    show_rational_number(add(x, y));
    cout << endl;

    cout << "x - y = ";
    show_rational_number(sub(x, y));
    cout << endl;

    cout << "x * y = ";
    show_rational_number(multi(x, y));
    cout << endl;

    cout << "x / y = ";
    show_rational_number(div(x, y));
    cout << endl;

    return 0;
}

使用方法

使用g++ 命令编译并调用：

g++ main.cpp rational_number.cpp -o main.exe
./main.exe

执行结果：