数据结构、算法与应用 （C++描述） 第二版 1.16

按照惯例，分了三个部分（头文件，头文件实现，main）来写。只是按照他的要求粗略的写了一下，没有优化。            **仅供有需要的人以参考，如有错误请纠正我**

头文件：currency.h

#ifndef CURRENCY_H_#define CURRENCY_H_#include<iostream>#include<exception>enum signType { plu, minu };class currency{private:    signType sign;    long amount;public:    currency(signType theSign = plu, unsigned long theDollars = 0, unsigned int theCents = 0);    ~currency() { }    void setValue(signType theSign, unsigned long Dollars, unsigned int Cents);    void setValue(double theAmount);    signType getSign() const;    unsigned long getDollars() const;    unsigned int getCents() const;    currency operator+(const currency & x) const;    friend std::ostream & operator<<(std::ostream & out, const currency &x);    void input();    void subtract(double x);    currency & percent(double x);    currency & multiply(double x);    currency & divide(double x);};#endif

头文件实现：currency.cpp

#include"currency.h"currency::currency(signType theSign, unsigned long theDollars, unsigned int theCents){    setValue(theSign, theDollars, theCents);}void currency::setValue(signType theSign, unsigned long Dollars, unsigned int Cents){    using namespace std;    if (Cents > 99)        throw "Cents should be < 100";    amount = Dollars * 100 + Cents;    if (theSign == minu)        amount = -amount;}void currency::setValue(double theAmount){    if (theAmount < 0)        amount = (long)((theAmount - 0.001) * 100);    else        amount = (long)((theAmount + 0.001) * 100);}signType currency::getSign() const{    if (amount < 0)        return minu;    else        return plu;}unsigned long currency::getDollars() const{    if (amount < 0)        return (-amount) / 100;    else        return amount / 100;}unsigned int currency::getCents() const{    if (amount < 0)        return -amount - getDollars() * 100;    else        return amount - getDollars() * 100;}currency currency::operator+(const currency & x) const{    currency result;    result.amount = amount + x.amount;    return result;}std::ostream & operator<<(std::ostream & out, const currency & x){    long theAmount = x.amount;    if (theAmount < 0)    {        out << '-';        theAmount = -theAmount;    }    long dollars = theAmount / 100;    out << '$' << dollars << '.';    int cents = theAmount - dollars * 100;    if (cents < 10)        out << '0';    out << cents;    return out;}void currency::input(){    using std::cin;    using std::cout;    using std::endl;    long dollars;    int cents;    cout << "Dollars: ";    cin >> dollars;    cout << "Cents: ";    cin >> cents;    if ((dollars > 0 && cents < 0) || (dollars < 0 && cents > 0))        throw "Dollars and cents symbols must be the same.";    if (dollars < 0)        setValue(minu, dollars, cents);    else        setValue(plu, dollars, cents);}void currency::subtract(double x){    amount = amount - (long)(x * 100);    std::cout << "subtract: " << *this << std::endl;}currency & currency::percent(double x){    amount = amount * (x / 100);    return *this;}currency & currency::multiply(double x){    amount = amount * x;    return *this;}currency & currency::divide(double x){    amount = amount / x;    return *this;}

测试文件：main.cpp

#include"currency.h"#include<iostream>#include<cstdlib>int main(){    using namespace std;    currency g, i, j;    currency h(plu, 3, 50);    g.setValue(minu, 2, 25);    i.setValue(-6.45);    j = h + g;    cout << h << " + " << g << " = " << j << endl;    j = i + g + h;    cout << i << " + " << g << " + " << h << " = " << j << endl;    /*异常测试    cout << "Attempting to initialize with cents = 152" << endl;    try    {        i.setValue(plu, 3, 152);    }    catch (char * e)    {        cout << "Caught thrown exception : " << e << endl;        exit(EXIT_FAILURE);    }    */    currency test;    try {        test.input();    }    catch (char * e)    {        cout << "test.input error: " << e << endl;        exit(EXIT_FAILURE);    }    cout << "test: " << test << endl;    test.subtract(2.5);    cout << "percent: " << test.percent(10) << endl;    cout << "multiply: " << test.multiply(5.0) << endl;    cout << "divide: " << test.divide(2.0) << endl;    return 0;}