题解 | #自动售货系统#
自动售货系统
https://www.nowcoder.com/practice/cd82dc8a4727404ca5d32fcb487c50bf
import java.util.*;
/*
1.难度不难，有耐心慢慢代码实现就好
2.读题也是一种能力，有几个坑描述没提到
3.默认的投币会加到存钱盒，以及退币减掉存钱盒里的钱币
4.好像直接实现商品和存钱盒类会更简洁易懂
*/
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
String[] ss = in.nextLine().split(";");
for (int i = 0; i < ss.length; i++) {
System.out.println(handle(ss[i]));
}
// System.out.println(handle("r 6-5-4-3-2-1 4-3-2-1"));
}
}
public static String handle(String s) {
String[] ss = s.split("\\s+");
// 1、系统初始化 r
if ("r".equals(ss[0])) {
return rInit(s);
}
// 2、投币 p
if ("p".equals(ss[0])) {
return pCoin(s);
}
// 3、购买商品 b
if ("b".equals(ss[0])) {
return bBuy(s);
}
// 4、退币 c
if ("c".equals(ss[0])) {
return cRefund(s);
}
// 5、查询 q
if ("q".equals(ss[0])) {
return qQuery(s);
}
return "E010:Parameter error";
}
static HashMap<String, Integer> merchandise;
static HashMap<String, Integer> currency;
static HashMap<String, Integer> merchandisePrice = new HashMap<>();
static {
merchandisePrice.put("A1", 2);
merchandisePrice.put("A2", 3);
merchandisePrice.put("A3", 4);
merchandisePrice.put("A4", 5);
merchandisePrice.put("A5", 8);
merchandisePrice.put("A6", 6);
}
public static String rInit(String s) {
//TODO
merchandise = new HashMap<>();
currency = new HashMap<>();
String[] ss1 = s.split(" ");
String[] ss2 = ss1[1].split("-");
String[] ss3 = ss1[2].split("-");
merchandise.put("A1", Integer.parseInt(ss2[0]));
merchandise.put("A2", Integer.parseInt(ss2[1]));
merchandise.put("A3", Integer.parseInt(ss2[2]));
merchandise.put("A4", Integer.parseInt(ss2[3]));
merchandise.put("A5", Integer.parseInt(ss2[4]));
merchandise.put("A6", Integer.parseInt(ss2[5]));
currency.put("1", Integer.parseInt(ss3[0]));
currency.put("2", Integer.parseInt(ss3[1]));
currency.put("5", Integer.parseInt(ss3[2]));
currency.put("10", Integer.parseInt(ss3[3]));
return "S001:Initialization is successful";
}
static int balance = 0;
public static String pCoin(String s) {
//TODO
String[] ss = s.split(" ");
// 如果投入非1元、2元、5元、10元的钱币面额
if (!"1".equals(ss[1]) && !"2".equals(ss[1]) && !"5".equals(ss[1]) &&
!"10".equals(ss[1])) {
return "E002:Denomination error";
}
// 如果存钱盒中1元和2元面额钱币总额小于本次投入的钱币面额
if (Integer.parseInt(ss[1]) != 1 && Integer.parseInt(ss[1]) != 2 && (currency.get("1") + currency.get("2") * 2) < Integer.parseInt(ss[1])) {
return "E003:Change is not enough, pay fail";
}
// 如果自动售货机中商品全部销售完毕
int count = 0;
for (String key : merchandise.keySet()) {
count += merchandise.get(key);
}
if (count == 0) {
return "E005:All the goods sold out";
}
// 如果投币成功
balance += Integer.parseInt(ss[1]);
currency.put(ss[1], currency.get(ss[1]) + 1);
return "S002:Pay success,balance=" + balance;
}
public static String bBuy(String s) {
//TODO
String[] ss = s.split(" ");
// 如果购买的商品不在商品列表中
if (!merchandise.containsKey(ss[1])) {
return "E006:Goods does not exist";
}
// 如果所购买的商品的数量为0
if (merchandise.get(ss[1]) == 0) {
return "E007:The goods sold out";
}
// 如果投币余额小于待购买商品价格
if (balance < merchandisePrice.get(ss[1])) {
return "E008:Lack of balance";
}
// 如果购买成功
balance -= merchandisePrice.get(ss[1]);
return "S003:Buy success,balance=" + balance;
}
public static String cRefund(String s) {
//TODO
// 如果投币余额等于0的情况下
if (balance == 0) {
return "E009:Work failure";
}
// 如果投币余额大于0的情况下，按照 退币原则 进行“找零”，输出退币信息；
int re1 = 0, re2 = 0, re5 = 0, re10 = 0;
if (balance >= 10) {
if (currency.get("10") >= balance / 10) {
re10 = balance / 10;
balance %= 10;
} else {
re10 = currency.get("10");
balance -= re10 * 10;
}
currency.put("10", currency.get("10") - re10);
}
if (balance >= 5) {
if (currency.get("5") >= balance / 5) {
re5 = balance / 5;
balance %= 5;
} else {
re5 = currency.get("5");
balance -= re5 * 5;
}
currency.put("5", currency.get("5") - re5);
}
if (balance >= 2) {
if (currency.get("2") >= balance / 2) {
re2 = balance / 2;
balance %= 2;
} else {
re2 = currency.get("2");
balance -= re2 * 2;
}
currency.put("2",currency.get("2") - re2);
}
if (balance >= 1) {
if (currency.get("1") >= balance) {
re1 = balance;
balance = 0;
} else {
re1 = currency.get("1");
balance -= re1;
}
currency.put("1",currency.get("1") - re1);
}
// balance = 0;
return "1 yuan coin number=" + re1 + "\n2 yuan coin number=" + re2 +
"\n5 yuan coin number=" + re5 + "\n10 yuan coin number=" + re10;
}
public static String qQuery(String s) {
//TODO
String[] ss = s.split(" ");
if (ss[1] == "0") {
String[] ssMerch = new String[6];
int idx = 0;
for(String key : merchandise.keySet()) {
ssMerch[idx] = merchandise.get(key) + " " + key + " " + merchandisePrice.get(key);
idx++;
}
Arrays.sort(ssMerch);
StringBuilder sb = new StringBuilder();
for(int i = 0; i < ssMerch.length; i++) {
sb.append(ssMerch[i] + "\n");
}
return sb.toString();
} else if (ss[1] == "1") {
return "1 yuan coin number=" + currency.get("1") + "\n2 yuan coin number=" + currency.get("2") + "\n5 yuan coin number=" + currency.get("5") + "\n10 yuan coin number=" + currency.get("10");
} else {
return "E010:Parameter error";
}
}
}