@@ -60,6 +60,14 @@ atm.withdraw(550); // 返回 [0,1,0,0,1] ，机器会返回 1 张 $50 的
6060
6161<!-- 这里可写通用的实现逻辑 -->
6262
63+ ** 方法一：模拟**
64+
65+ 我们用一个数组 $d$ 记录钞票面额，用一个数组 $cnt$ 记录每种面额的钞票数量。
66+
67+ 对于 ` deposit ` 操作，我们只需要将对应面额的钞票数量加上即可。时间复杂度 $O(1)$。
68+
69+ 对于 ` withdraw ` 操作，我们从大到小枚举每种面额的钞票，取出尽可能多且不超过 $amount$ 的钞票，然后将 $amount$ 减去取出的钞票面额之和，如果最后 $amount$ 仍大于 $0$，说明无法取出 $amount$ 的钞票，返回 $-1$ 即可。否则，返回取出的钞票数量即可。时间复杂度 $O(1)$。
70+
6371<!-- tabs:start -->
6472
6573### ** Python3**
@@ -70,22 +78,22 @@ atm.withdraw(550); // 返回 [0,1,0,0,1] ，机器会返回 1 张 $50 的
7078class ATM :
7179 def __init__ (self
7280 self .cnt = [0 ] * 5
73- self .m = [500 , 200 , 100 , 50 , 20 ]
81+ self .d = [20 , 50 , 100 , 200 , 500 ]
7482
7583 def deposit (self banknotesCount : List[int ]) -> None :
76- for i, v in enumerate (banknotesCount[:: - 1 ] ):
84+ for i, v in enumerate (banknotesCount):
7785 self .cnt[i] += v
7886
7987 def withdraw (self amount : int ) -> List[int ]:
8088 ans = [0 ] * 5
81- for i, n in enumerate ( self .cnt ):
82- ans[i] = min (amount // self .m [i], n )
83- amount -= self .m [i] * ans [i]
89+ for i in range ( 4 , - 1 , - 1 ):
90+ ans[i] = min (amount // self .d [i], self .cnt[i] )
91+ amount -= ans [i] * self .d [i]
8492 if amount > 0 :
8593 return [- 1 ]
8694 for i, v in enumerate (ans):
8795 self .cnt[i] -= v
88- return ans[:: - 1 ]
96+ return ans
8997
9098
9199# Your ATM object will be instantiated and called as such:
@@ -99,7 +107,133 @@ class ATM:
99107<!-- 这里可写当前语言的特殊实现逻辑 -->
100108
101109``` java
110+ class ATM {
111+ private long [] cnt = new long [5 ];
112+ private int [] d = {20 , 50 , 100 , 200 , 500 };
113+
114+ public ATM () {
115+
116+ }
117+
118+ public void deposit (int [] banknotesCount ) {
119+ for (int i = 0 ; i < banknotesCount. length; ++ i) {
120+ cnt[i] += banknotesCount[i];
121+ }
122+ }
123+
124+ public int [] withdraw (int amount ) {
125+ int [] ans = new int [5 ];
126+ for (int i = 4 ; i >= 0 ; -- i) {
127+ ans[i] = (int ) Math . min(amount / d[i], cnt[i]);
128+ amount -= ans[i] * d[i];
129+ }
130+ if (amount > 0 ) {
131+ return new int [] {- 1 };
132+ }
133+ for (int i = 0 ; i < 5 ; ++ i) {
134+ cnt[i] -= ans[i];
135+ }
136+ return ans;
137+ }
138+ }
139+
140+ /**
141+ * Your ATM object will be instantiated and called as such:
142+ * ATM obj = new ATM();
143+ * obj.deposit(banknotesCount);
144+ * int[] param_2 = obj.withdraw(amount);
145+ */
146+ ```
147+
148+ ### ** C++**
149+
150+ ``` cpp
151+ class ATM {
152+ public:
153+ ATM() {
154+
155+ }
156+
157+ void deposit (vector<int > banknotesCount) {
158+ for (int i = 0; i < banknotesCount.size(); ++i) {
159+ cnt[ i] += banknotesCount[ i] ;
160+ }
161+ }
162+
163+ vector<int> withdraw(int amount) {
164+ vector<int> ans(5);
165+ for (int i = 4; ~i; --i) {
166+ ans[i] = min(1ll * amount / d[i], cnt[i]);
167+ amount -= ans[i] * d[i];
168+ }
169+ if (amount > 0) {
170+ return {-1};
171+ }
172+ for (int i = 0; i < 5; ++i) {
173+ cnt[i] -= ans[i];
174+ }
175+ return ans;
176+ }
177+
178+ private:
179+ long long cnt[ 5] = {0};
180+ int d[ 5] = {20, 50, 100, 200, 500};
181+ };
182+
183+ /**
184+ * Your ATM object will be instantiated and called as such:
185+ * ATM* obj = new ATM();
186+ * obj->deposit(banknotesCount);
187+ * vector<int > param_2 = obj->withdraw(amount);
188+ * /
189+ ```
102190
191+ ### **Go**
192+
193+ ```go
194+ type ATM struct {
195+ d [5]int
196+ cnt [5]int
197+ }
198+
199+ func Constructor() ATM {
200+ return ATM{[5]int{20, 50, 100, 200, 500}, [5]int{}}
201+ }
202+
203+ func (this *ATM) Deposit(banknotesCount []int) {
204+ for i, v := range banknotesCount {
205+ this.cnt[i] += v
206+ }
207+ }
208+
209+ func (this *ATM) Withdraw(amount int) []int {
210+ ans := make([]int, 5)
211+ for i := 4; i >= 0; i-- {
212+ ans[i] = min(amount/this.d[i], this.cnt[i])
213+ amount -= ans[i] * this.d[i]
214+ }
215+ if amount > 0 {
216+ return []int{-1}
217+ }
218+ for i, v := range ans {
219+ this.cnt[i] -= v
220+ }
221+ return ans
222+ }
223+
224+ func min(a, b int) int {
225+ if a < b {
226+ return a
227+ }
228+ return b
229+ }
230+
231+ /**
232+ * Your ATM object will be instantiated and called as such:
233+ * obj := Constructor();
234+ * obj.Deposit(banknotesCount);
235+ * param_2 := obj.Withdraw(amount);
236+ */
103237```
104238
105239### ** TypeScript**
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