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48 lines
2.8 KiB
HTML
48 lines
2.8 KiB
HTML
<p>Design your implementation of the circular double-ended queue (deque).</p>
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<p>Implement the <code>MyCircularDeque</code> class:</p>
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<ul>
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<li><code>MyCircularDeque(int k)</code> Initializes the deque with a maximum size of <code>k</code>.</li>
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<li><code>boolean insertFront()</code> Adds an item at the front of Deque. Returns <code>true</code> if the operation is successful, or <code>false</code> otherwise.</li>
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<li><code>boolean insertLast()</code> Adds an item at the rear of Deque. Returns <code>true</code> if the operation is successful, or <code>false</code> otherwise.</li>
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<li><code>boolean deleteFront()</code> Deletes an item from the front of Deque. Returns <code>true</code> if the operation is successful, or <code>false</code> otherwise.</li>
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<li><code>boolean deleteLast()</code> Deletes an item from the rear of Deque. Returns <code>true</code> if the operation is successful, or <code>false</code> otherwise.</li>
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<li><code>int getFront()</code> Returns the front item from the Deque. Returns <code>-1</code> if the deque is empty.</li>
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<li><code>int getRear()</code> Returns the last item from Deque. Returns <code>-1</code> if the deque is empty.</li>
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<li><code>boolean isEmpty()</code> Returns <code>true</code> if the deque is empty, or <code>false</code> otherwise.</li>
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<li><code>boolean isFull()</code> Returns <code>true</code> if the deque is full, or <code>false</code> otherwise.</li>
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</ul>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input</strong>
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["MyCircularDeque", "insertLast", "insertLast", "insertFront", "insertFront", "getRear", "isFull", "deleteLast", "insertFront", "getFront"]
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[[3], [1], [2], [3], [4], [], [], [], [4], []]
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<strong>Output</strong>
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[null, true, true, true, false, 2, true, true, true, 4]
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<strong>Explanation</strong>
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MyCircularDeque myCircularDeque = new MyCircularDeque(3);
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myCircularDeque.insertLast(1); // return True
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myCircularDeque.insertLast(2); // return True
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myCircularDeque.insertFront(3); // return True
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myCircularDeque.insertFront(4); // return False, the queue is full.
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myCircularDeque.getRear(); // return 2
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myCircularDeque.isFull(); // return True
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myCircularDeque.deleteLast(); // return True
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myCircularDeque.insertFront(4); // return True
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myCircularDeque.getFront(); // return 4
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= k <= 1000</code></li>
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<li><code>0 <= value <= 1000</code></li>
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<li>At most <code>2000</code> calls will be made to <code>insertFront</code>, <code>insertLast</code>, <code>deleteFront</code>, <code>deleteLast</code>, <code>getFront</code>, <code>getRear</code>, <code>isEmpty</code>, <code>isFull</code>.</li>
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</ul>
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