@@ -45,27 +45,214 @@ circularDeque.getFront(); // 返回 4
4545 <li>请不要使用内置的双端队列库。</li>
4646</ul >
4747
48-
4948## 解法
5049
5150<!-- 这里可写通用的实现逻辑 -->
5251
52+ “循环数组”实现。
53+
5354<!-- tabs:start -->
5455
5556### ** Python3**
5657
5758<!-- 这里可写当前语言的特殊实现逻辑 -->
5859
5960``` python
61+ class MyCircularDeque :
62+
63+ def __init__ (self k : int ):
64+ """
65+ Initialize your data structure here. Set the size of the deque to be k.
66+ """
67+ self .q = [0 ] * k
68+ self .front = 0
69+ self .size = 0
70+ self .capacity = k
71+
72+ def insertFront (self value : int ) -> bool :
73+ """
74+ Adds an item at the front of Deque. Return true if the operation is successful.
75+ """
76+ if self .isFull():
77+ return False
78+ if not self .isEmpty():
79+ self .front = (self .front - 1 + self .capacity) % self .capacity
80+ self .q[self .front] = value
81+ self .size += 1
82+ return True
83+
84+ def insertLast (self value : int ) -> bool :
85+ """
86+ Adds an item at the rear of Deque. Return true if the operation is successful.
87+ """
88+ if self .isFull():
89+ return False
90+ idx = (self .front + self .size) % self .capacity
91+ self .q[idx] = value
92+ self .size += 1
93+ return True
94+
95+ def deleteFront (self bool :
96+ """
97+ Deletes an item from the front of Deque. Return true if the operation is successful.
98+ """
99+ if self .isEmpty():
100+ return False
101+ self .front = (self .front + 1 ) % self .capacity
102+ self .size -= 1
103+ return True
104+
105+ def deleteLast (self bool :
106+ """
107+ Deletes an item from the rear of Deque. Return true if the operation is successful.
108+ """
109+ if self .isEmpty():
110+ return False
111+ self .size -= 1
112+ return True
113+
114+ def getFront (self int :
115+ """
116+ Get the front item from the deque.
117+ """
118+ if self .isEmpty():
119+ return - 1
120+ return self .q[self .front]
121+
122+ def getRear (self int :
123+ """
124+ Get the last item from the deque.
125+ """
126+ if self .isEmpty():
127+ return - 1
128+ idx = (self .front + self .size - 1 ) % self .capacity
129+ return self .q[idx]
130+
131+ def isEmpty (self bool :
132+ """
133+ Checks whether the circular deque is empty or not.
134+ """
135+ return self .size == 0
136+
137+ def isFull (self bool :
138+ """
139+ Checks whether the circular deque is full or not.
140+ """
141+ return self .size == self .capacity
60142
143+
144+ # Your MyCircularDeque object will be instantiated and called as such:
145+ # obj = MyCircularDeque(k)
146+ # param_1 = obj.insertFront(value)
147+ # param_2 = obj.insertLast(value)
148+ # param_3 = obj.deleteFront()
149+ # param_4 = obj.deleteLast()
150+ # param_5 = obj.getFront()
151+ # param_6 = obj.getRear()
152+ # param_7 = obj.isEmpty()
153+ # param_8 = obj.isFull()
61154```
62155
63156### ** Java**
64157
65158<!-- 这里可写当前语言的特殊实现逻辑 -->
66159
67160``` java
161+ class MyCircularDeque {
162+ private int [] q;
163+ private int front;
164+ private int size;
165+ private int capacity;
166+
167+ /* * Initialize your data structure here. Set the size of the deque to be k. */
168+ public MyCircularDeque (int k ) {
169+ q = new int [k];
170+ capacity = k;
171+ }
172+
173+ /* * Adds an item at the front of Deque. Return true if the operation is successful. */
174+ public boolean insertFront (int value ) {
175+ if (isFull()) {
176+ return false ;
177+ }
178+ if (! isEmpty()) {
179+ front = (front - 1 + capacity) % capacity;
180+ }
181+ q[front] = value;
182+ ++ size;
183+ return true ;
184+ }
185+
186+ /* * Adds an item at the rear of Deque. Return true if the operation is successful. */
187+ public boolean insertLast (int value ) {
188+ if (isFull()) {
189+ return false ;
190+ }
191+ int idx = (front + size) % capacity;
192+ q[idx] = value;
193+ ++ size;
194+ return true ;
195+ }
196+
197+ /* * Deletes an item from the front of Deque. Return true if the operation is successful. */
198+ public boolean deleteFront () {
199+ if (isEmpty()) {
200+ return false ;
201+ }
202+ front = (front + 1 ) % capacity;
203+ -- size;
204+ return true ;
205+ }
206+
207+ /* * Deletes an item from the rear of Deque. Return true if the operation is successful. */
208+ public boolean deleteLast () {
209+ if (isEmpty()) {
210+ return false ;
211+ }
212+ -- size;
213+ return true ;
214+ }
215+
216+ /* * Get the front item from the deque. */
217+ public int getFront () {
218+ if (isEmpty()) {
219+ return - 1 ;
220+ }
221+ return q[front];
222+ }
223+
224+ /* * Get the last item from the deque. */
225+ public int getRear () {
226+ if (isEmpty()) {
227+ return - 1 ;
228+ }
229+ int idx = (front + size - 1 ) % capacity;
230+ return q[idx];
231+ }
232+
233+ /* * Checks whether the circular deque is empty or not. */
234+ public boolean isEmpty () {
235+ return size == 0 ;
236+ }
237+
238+ /* * Checks whether the circular deque is full or not. */
239+ public boolean isFull () {
240+ return size == capacity;
241+ }
242+ }
68243
244+ /**
245+ * Your MyCircularDeque object will be instantiated and called as such:
246+ * MyCircularDeque obj = new MyCircularDeque(k);
247+ * boolean param_1 = obj.insertFront(value);
248+ * boolean param_2 = obj.insertLast(value);
249+ * boolean param_3 = obj.deleteFront();
250+ * boolean param_4 = obj.deleteLast();
251+ * int param_5 = obj.getFront();
252+ * int param_6 = obj.getRear();
253+ * boolean param_7 = obj.isEmpty();
254+ * boolean param_8 = obj.isFull();
255+ */
69256```
70257
71258### ** ...**
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