Question

以下代码并未计算在Java“收银机”中分发更改的最佳方式。我该如何解决？

public void generateUSDChange(){
    change = payment-purchase;
    quarters = (int) (change/.25);
    change -= (quarters * .25);
    dimes = (int) (change/.1);
    change -= (dimes * .1);
    nickels = (int) (change/.05);
    change -= (nickels * .05);
    pennies = (int) (change/.01);
    changeamount = quarters*.25 + dimes*.1 + nickels*.05 + pennies*.01;
    if(changeamount != (payment-purchase)){
        pennies++;
        if(pennies>=5){
            nickels++;
            pennies-=5;
        }
        if(nickels>=2){
            dimes++;
            nickels-=2;
        }
        if(((dimes*.1) + (nickels*.05)) >= .25){
            quarters++;
            dimes-=2;
            nickels--;
        }
    }
}

Answer 1

其他人也建议双重和浮动不利于货币。您可以使用BigDecimal。这是工作代码：

import java.math.BigDecimal;
import java.util.LinkedHashMap;
import java.util.Map;

public enum CurrencyDenomination {

HUNDRED(BigDecimal.valueOf(100)), FIFTY(BigDecimal.valueOf(50)), TWENTY(BigDecimal.valueOf(20)), 
        TEN(BigDecimal.valueOf(10)), FIVE(BigDecimal.valueOf(5)), ONE(BigDecimal.valueOf(1)), 
                QUARTER(BigDecimal.valueOf(.25)), DIME(BigDecimal.valueOf(.10)), 
                        NICLE(BigDecimal.valueOf(.05)), PENNIES(BigDecimal.valueOf(.01));

private BigDecimal value;

CurrencyDenomination(BigDecimal value) {
    this.value = value;
}

public static Map<CurrencyDenomination, Integer> calculate(BigDecimal balance) {
    Map<CurrencyDenomination, Integer> balanceCurrency = new LinkedHashMap<CurrencyDenomination, Integer>();
    BigDecimal leftOver = balance;
    System.out.println("Given amount : "+balance);
    for (CurrencyDenomination currencyDenomination : CurrencyDenomination
            .values()) {

        int count = leftOver.divide(currencyDenomination.value).intValue();

        if (leftOver != BigDecimal.ZERO) {
            if (balanceCurrency.containsKey(currencyDenomination)) {
                int existingCount = balanceCurrency
                        .get(currencyDenomination);
                existingCount = existingCount + count;
                balanceCurrency.put(currencyDenomination, existingCount);
            } else {
                balanceCurrency.put(currencyDenomination, count);
            }
        }

        leftOver = leftOver.remainder(currencyDenomination.value);

        if (leftOver.equals(BigDecimal.ZERO)) {
            break;
        }
    }
    return balanceCurrency;
}

public static void main(String[] args) {
    System.out.println("BalanceCurrency : "+calculate(BigDecimal.valueOf(49.52)));
}
}

输出：

Given amount : 49.52
BalanceCurrency : {HUNDRED=0, FIFTY=0, TWENTY=2, TEN=0, FIVE=1, ONE=4, QUARTER=2, DIME=0, NICLE=0, PENNIES=2}

Answer 2

我同意上述答案和关于使用BigDecimal的评论。处理它的另一种方法是使用代表美分的整数值，假设您使用的是美元货币。你可以尝试这样的事情。（货币金额只是简单测试的示例）

public void generateUSDChange(){
int payment = 500; //$5.00
int purchase = 268; //$2.68
int change = payment - purchase;
int quarters = change / 25;
change = change % 25;
int dimes = change / 10;
change = change % 10;
int nickles = change / 5;
int pennies = change % 5;
System.out.println("Your change is " + quarters + " quarters " + dimes + " dimes " + nickles + " nickles, and "+ pennies + " pennies.");
int change = pennies * 1 + nickles * 5 + dimes * 10 + quarters * 25;
System.out.printf("Your change totals to $%d.%02d", change/100, change%100);}

收银机变更问题

2 个答案: