{ "data": { "question": { "questionId": "2352", "questionFrontendId": "2241", "categoryTitle": "Algorithms", "boundTopicId": 1422461, "title": "Design an ATM Machine", "titleSlug": "design-an-atm-machine", "content": "
There is an ATM machine that stores banknotes of 5
denominations: 20
, 50
, 100
, 200
, and 500
dollars. Initially the ATM is empty. The user can use the machine to deposit or withdraw any amount of money.
When withdrawing, the machine prioritizes using banknotes of larger values.
\n\n$300
and there are 2
$50
banknotes, 1
$100
banknote, and 1
$200
banknote, then the machine will use the $100
and $200
banknotes.$600
and there are 3
$200
banknotes and 1
$500
banknote, then the withdraw request will be rejected because the machine will first try to use the $500
banknote and then be unable to use banknotes to complete the remaining $100
. Note that the machine is not allowed to use the $200
banknotes instead of the $500
banknote.Implement the ATM class:
\n\nATM()
Initializes the ATM object.void deposit(int[] banknotesCount)
Deposits new banknotes in the order $20
, $50
, $100
, $200
, and $500
.int[] withdraw(int amount)
Returns an array of length 5
of the number of banknotes that will be handed to the user in the order $20
, $50
, $100
, $200
, and $500
, and update the number of banknotes in the ATM after withdrawing. Returns [-1]
if it is not possible (do not withdraw any banknotes in this case).\n
Example 1:
\n\n\nInput\n["ATM", "deposit", "withdraw", "deposit", "withdraw", "withdraw"]\n[[], [[0,0,1,2,1]], [600], [[0,1,0,1,1]], [600], [550]]\nOutput\n[null, null, [0,0,1,0,1], null, [-1], [0,1,0,0,1]]\n\nExplanation\nATM atm = new ATM();\natm.deposit([0,0,1,2,1]); // Deposits 1 $100 banknote, 2 $200 banknotes,\n // and 1 $500 banknote.\natm.withdraw(600); // Returns [0,0,1,0,1]. The machine uses 1 $100 banknote\n // and 1 $500 banknote. The banknotes left over in the\n // machine are [0,0,0,2,0].\natm.deposit([0,1,0,1,1]); // Deposits 1 $50, $200, and $500 banknote.\n // The banknotes in the machine are now [0,1,0,3,1].\natm.withdraw(600); // Returns [-1]. The machine will try to use a $500 banknote\n // and then be unable to complete the remaining $100,\n // so the withdraw request will be rejected.\n // Since the request is rejected, the number of banknotes\n // in the machine is not modified.\natm.withdraw(550); // Returns [0,1,0,0,1]. The machine uses 1 $50 banknote\n // and 1 $500 banknote.\n\n
\n
Constraints:
\n\nbanknotesCount.length == 5
0 <= banknotesCount[i] <= 109
1 <= amount <= 109
5000
calls in total will be made to withdraw
and deposit
.withdraw
and deposit
.banknotesCount[i]
in all deposits doesn't exceed 109
一个 ATM 机器,存有 5
种面值的钞票:20
,50
,100
,200
和 500
美元。初始时,ATM 机是空的。用户可以用它存或者取任意数目的钱。
取款时,机器会优先取 较大 数额的钱。
\n\n$300
,并且机器里有 2
张 $50
的钞票,1
张 $100
的钞票和1
张 $200
的钞票,那么机器会取出 $100
和 $200
的钞票。$600
,机器里有 3
张 $200
的钞票和1
张 $500
的钞票,那么取款请求会被拒绝,因为机器会先取出 $500
的钞票,然后无法取出剩余的 $100
。注意,因为有 $500
钞票的存在,机器 不能 取 $200
的钞票。请你实现 ATM 类:
\n\nATM()
初始化 ATM 对象。void deposit(int[] banknotesCount)
分别存入 $20
,$50
,$100
,$200
和 $500
钞票的数目。int[] withdraw(int amount)
返回一个长度为 5
的数组,分别表示 $20
,$50
,$100
,$200
和 $500
钞票的数目,并且更新 ATM 机里取款后钞票的剩余数量。如果无法取出指定数额的钱,请返回 [-1]
(这种情况下 不 取出任何钞票)。\n\n
示例 1:
\n\n\n输入:\n[\"ATM\", \"deposit\", \"withdraw\", \"deposit\", \"withdraw\", \"withdraw\"]\n[[], [[0,0,1,2,1]], [600], [[0,1,0,1,1]], [600], [550]]\n输出:\n[null, null, [0,0,1,0,1], null, [-1], [0,1,0,0,1]]\n\n解释:\nATM atm = new ATM();\natm.deposit([0,0,1,2,1]); // 存入 1 张 $100 ,2 张 $200 和 1 张 $500 的钞票。\natm.withdraw(600); // 返回 [0,0,1,0,1] 。机器返回 1 张 $100 和 1 张 $500 的钞票。机器里剩余钞票的数量为 [0,0,0,2,0] 。\natm.deposit([0,1,0,1,1]); // 存入 1 张 $50 ,1 张 $200 和 1 张 $500 的钞票。\n // 机器中剩余钞票数量为 [0,1,0,3,1] 。\natm.withdraw(600); // 返回 [-1] 。机器会尝试取出 $500 的钞票,然后无法得到剩余的 $100 ,所以取款请求会被拒绝。\n // 由于请求被拒绝,机器中钞票的数量不会发生改变。\natm.withdraw(550); // 返回 [0,1,0,0,1] ,机器会返回 1 张 $50 的钞票和 1 张 $500 的钞票。\n\n
\n\n
提示:
\n\nbanknotesCount.length == 5
0 <= banknotesCount[i] <= 109
1 <= amount <= 109
5000
次 withdraw
和 deposit
的调用。withdraw
和 deposit
至少各有 一次 调用。\\u7248\\u672c\\uff1a \\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 \\u4e3a\\u4e86\\u4f7f\\u7528\\u65b9\\u4fbf\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8\\u5bfc\\u5165\\u3002<\\/p>\"],\"java\":[\"Java\",\" \\u7248\\u672c\\uff1a \\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u88ab\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n \\u5305\\u542b Pair \\u7c7b: https:\\/\\/docs.oracle.com\\/javase\\/8\\/javafx\\/api\\/javafx\\/util\\/Pair.html <\\/p>\"],\"python\":[\"Python\",\" \\u7248\\u672c\\uff1a \\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u5e38\\u7528\\u5e93\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8 \\u5bfc\\u5165\\uff0c\\u5982\\uff1aarray<\\/a>, bisect<\\/a>, 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