Question

我的程序有两个功能。一种可以计算一美元金额的票据类型，另一种可以显示该金额。

我来自Java背景，我不太了解C ++语法，希望能提供一些帮助。

#include <iostream>
#include <iomanip>
using namespace std;

//function declaration
void calcChange(int amount, int* twenties, int* tens, int* fives, int*ones);
void showChange(int amount, int twenties, int tens, int fives, int ones);

int main() {

//Declaration
int amount =0;

//Call to function
calcChange(&twenties, &tens, &fives, &ones);

showChange(twenties,tens,fives,ones);
do {

    cout << "Enter amount (or negative to terminate):" << endl;
    cin >> amount;


    //if loop that ans if 0 is invalid output
    if (amount == 0) {
    cout << "Invalid dollar amount.\n";
}


    //put output here
   cout << "Amount "  << setw(2) << "Twenties " << setw(2) << "Tens " << setw(5) <<"fives "<< setw(5) <<"Ones "<< endl;

   cout << amount  << setw(2) << twenties << setw(2) << tens << setw(5) << fives << setw(5) << ones << endl;


}while (amount >= 0);
    cout << "Goodbye!";
    return 0;
}

//function declarations
void calcChange(int amount, int* twenties, int* tens, int* fives, int* ones) 
{
    while(amount >= 20){
        *twenties = amount/20;amount % 20;
        amount = *twenties;
        twenties++;
    }

    while(amount >=10){
        *tens = amount/10; amount % 10;
        amount=*tens;
        tens++;
    }

    while(amount >=5){
        *fives = amount/5; amount % 5;
        amount = *fives;
        fives++;
    }

    while(amount >=1){
        *ones = amount/1; amount % 1;
        amount = *ones;
        ones++;
    }

    return;
}


void showChange(int amount, int twenties, int tens, int fives, int ones) {

    twenties = twenties;
    tens = tens;
    fives = fives;
    ones = ones;
    return;
}

Answer 1

首先，不确定要使用showChange

做什么。

函数声明

void calcChange(int amount, int* twenties, int* tens, int* fives, int* ones);

函数定义（不是声明）

void calcChange(int amount, int* twenties, int* tens, int* fives, int* ones) 
{
    *twenties = amount / 20;  amount %= 20;
    *tens = amount / 10;      amount %= 10; 
    *fives = amount / 5;      amount %= 5;
    *ones = amount / 1;       amount %= 1;
    return;
}

主要功能

int main() {
    int amount = 0;
    do {
        cout << "Enter amount (or negative to terminate):" << endl;
        cin >> amount;

        if (amount == 0) {
            cout << "Invalid dollar amount.\n";
            break;
        }

        int twenties, tens, fives, ones;
        calcChange(amount, &twenties, &tens, &fives, &ones);

        cout << "Amount "  << setw(2) << "Twenties " << setw(2) << "Tens " << setw(5) <<"fives "<< setw(5) <<"Ones "<< endl;
        cout << amount  << setw(2) << twenties << setw(2) << tens << setw(5) << fives << setw(5) << ones << endl;
    } while (amount >= 0);
    cout << "Goodbye!";
    return 0;
}

C ++中的指针和函数

1 个答案: