Create design-circular-queue.cpp

Author: kamyu104

C++/design-circular-queue.cpp

@@ -0,0 +1,70 @@
+// Time:  O(1)
+// Space: O(k)
+
+class MyCircularQueue {
+public:
+    /** Initialize your data structure here. Set the size of the queue to be k. */
+    MyCircularQueue(int k) :
+        start_(0),
+        size_(0),
+        buffer_(k, 0) {
+        
+    }
+    
+    /** Insert an element into the circular queue. Return true if the operation is successful. */
+    bool enQueue(int value) {
+        if (isFull()) {
+            return false;
+        }
+        buffer_[(start_ + size_) % buffer_.size()] = value;
+        ++size_;
+        return true;
+    }
+    
+    /** Delete an element from the circular queue. Return true if the operation is successful. */
+    bool deQueue() {
+        if (isEmpty()) {
+            return false;
+        }
+        start_ = (start_ + 1) % buffer_.size();
+        --size_;
+        return true;
+    }
+    
+    /** Get the front item from the queue. */
+    int Front() {
+        return isEmpty() ? -1 : buffer_[start_];
+    }
+    
+    /** Get the last item from the queue. */
+    int Rear() {
+        return isEmpty() ? -1 : buffer_[(start_ + size_ - 1) % buffer_.size()];
+    }
+    
+    /** Checks whether the circular queue is empty or not. */
+    bool isEmpty() {
+        return size_ == 0;
+    }
+    
+    /** Checks whether the circular queue is full or not. */
+    bool isFull() {
+        return size_ == buffer_.size();
+    }
+
+private:
+    int start_;
+    int size_;
+    vector<int> buffer_;
+};
+
+/**
+ * Your MyCircularQueue object will be instantiated and called as such:
+ * MyCircularQueue obj = new MyCircularQueue(k);
+ * bool param_1 = obj.enQueue(value);
+ * bool param_2 = obj.deQueue();
+ * int param_3 = obj.Front();
+ * int param_4 = obj.Rear();
+ * bool param_5 = obj.isEmpty();
+ * bool param_6 = obj.isFull();
+ */
+