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50 lines
2.8 KiB
HTML
50 lines
2.8 KiB
HTML
<p>Design your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle, and the last position is connected back to the first position to make a circle. It is also called "Ring Buffer".</p>
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<p>One of the benefits of the circular queue is that we can make use of the spaces in front of the queue. In a normal queue, once the queue becomes full, we cannot insert the next element even if there is a space in front of the queue. But using the circular queue, we can use the space to store new values.</p>
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<p>Implement the <code>MyCircularQueue</code> class:</p>
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<ul>
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<li><code>MyCircularQueue(k)</code> Initializes the object with the size of the queue to be <code>k</code>.</li>
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<li><code>int Front()</code> Gets the front item from the queue. If the queue is empty, return <code>-1</code>.</li>
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<li><code>int Rear()</code> Gets the last item from the queue. If the queue is empty, return <code>-1</code>.</li>
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<li><code>boolean enQueue(int value)</code> Inserts an element into the circular queue. Return <code>true</code> if the operation is successful.</li>
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<li><code>boolean deQueue()</code> Deletes an element from the circular queue. Return <code>true</code> if the operation is successful.</li>
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<li><code>boolean isEmpty()</code> Checks whether the circular queue is empty or not.</li>
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<li><code>boolean isFull()</code> Checks whether the circular queue is full or not.</li>
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</ul>
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<p>You must solve the problem without using the built-in queue data structure in your programming language. </p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<pre>
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<strong>Input</strong>
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["MyCircularQueue", "enQueue", "enQueue", "enQueue", "enQueue", "Rear", "isFull", "deQueue", "enQueue", "Rear"]
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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, 3, true, true, true, 4]
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<strong>Explanation</strong>
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MyCircularQueue myCircularQueue = new MyCircularQueue(3);
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myCircularQueue.enQueue(1); // return True
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myCircularQueue.enQueue(2); // return True
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myCircularQueue.enQueue(3); // return True
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myCircularQueue.enQueue(4); // return False
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myCircularQueue.Rear(); // return 3
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myCircularQueue.isFull(); // return True
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myCircularQueue.deQueue(); // return True
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myCircularQueue.enQueue(4); // return True
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myCircularQueue.Rear(); // 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>3000</code> calls will be made to <code>enQueue</code>, <code>deQueue</code>, <code>Front</code>, <code>Rear</code>, <code>isEmpty</code>, and <code>isFull</code>.</li>
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</ul>
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