我从一位经验丰富的程序员那里解决了这个问题，为编程测试做准备。
问题：
根据购买金额和付款金额，计算作为变更返回的每种货币面额的数量和类型。总是以最高面额的大多数给出变化。使用纸币的面额将分别为100美元，50美元，20美元，10美元，5美元和1美元。硬币的面额将分别为0.25美元，0.10美元，0.05美元和0.01美元。
INPUT：将有5行输入。每行将包含2个有理数字，表示购买金额和付款金额。
输出：对于每个输入行，使用按其数量级从高到低的顺序使用的非零面额数打印更改。如果没有更改，则打印NONE。样本输出＃1代表：1- $ 5,2- $ 1,1- $ 25,2- $ 10和2 - $。01。
示例输入样本输出
1. 12.53,20.00 1. 121221
2. 11.33,15.00 2. 32112
3. 35.64,50.00 3. 14111
4. 72.67,100.00 4. 112113
5. 106.68,200.00 5. 123112
我决定创建两个程序：一个很长，更容易跟随的程序和一个简洁版本。
这是漫长的：
import java.util.*;
public class Prac13CorrectChange {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
for (int A = 1; A <= 5; A++) {
System.out
.println("What is the amount of your purchase and the amount given as your payment?");
String input = in.nextLine();
String[] data = input.split(",");
double $amount = Double.parseDouble(data[0]);
double price = Double.parseDouble(data[1]);
double change = price - $amount;
int ans1 = ((int) (change / 100));
change = change - (ans1 * 100);
int ans2 = ((int) (change / 50));
change = change - (ans2 * 50);
int ans3 = ((int) (change / 20));
change = change - (ans3 * 20);
int ans4 = ((int) (change / 10));
change = change - (ans4 * 10);
int ans5 = ((int) (change / 5));
change = change - (ans5 * 5);
int ans6 = ((int) (change / 1));
change = change - (ans6 * 1);
int ans7 = ((int) (change / .25));
change = change - (ans7 * .25);
int ans8 = ((int) (change / .10));
change = change - (ans8 * .10);
int ans9 = ((int) (change / .05));
change = change - (ans9 * .05);
int ans10 = ((int) (change / .01));
change = change - (ans10 * .01);
String answer = "";
if (ans1 != 0) {
answer = answer + Integer.toString(ans1);
}
if (ans2 != 0) {
answer = answer + Integer.toString(ans2);
}
if (ans3 != 0) {
answer = answer + Integer.toString(ans3);
}
if (ans4 != 0) {
answer = answer + Integer.toString(ans4);
}
if (ans5 != 0) {
answer = answer + Integer.toString(ans5);
}
if (ans6 != 0) {
answer = answer + Integer.toString(ans6);
}
if (ans7 != 0) {
answer = answer + Integer.toString(ans7);
}
if (ans8 != 0) {
answer = answer + Integer.toString(ans8);
}
if (ans9 != 0) {
answer = answer + Integer.toString(ans9);
}
if (ans10 != 0) {
answer = answer + Integer.toString(ans10);
}
System.out.println(answer);
}
}
}
这是精简版。
import java.util.Scanner;
public class Prac15CorrectChangeShort {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
for (int A = 1; A <= 5; A++) {
System.out
.println("What is the amount of your purchase and the amount given as your payment?");
String input = in.nextLine();
String[] data = input.split(",");
double $amount = Double.parseDouble(data[0]);
double price = Double.parseDouble(data[1]);
double change = price - $amount;
int ans[] = new int[10];
double money[] = { 100, 50, 20, 10, 5, 1, 0.25, 0.10, 0.05, 0.01 };
for (int looptimes = 0; looptimes < 10; looptimes++) {
ans[looptimes] = ((int) (change / money[looptimes]));
change = change - (ans[looptimes] * money[looptimes]);
}
for (int looptimes = 0; looptimes < 10; looptimes++) {
if (ans[looptimes] != 0) {
System.out.print(ans[looptimes]);
}
}
System.out.print('\n');
}
}
}
我遇到的主要问题是，无论我做什么调试，它都会给我不正确的输出＃2-5。它给了我最后一位数减1。既没有给我这个问题的程序员，也没有找到任何理由。
请帮忙。
答案 0 :(得分：2)
看起来像是浮点错误。
在计算更改时，您可以使用BigDecimal而不是double。
BigDecimal change = BigDecimal.valueOf(price - $amount);