Create design-circular-deque.cpp

Author: kamyu104

C++/design-circular-deque.cpp

@@ -0,0 +1,92 @@
+// Time:  O(1)
+// Space: O(k)
+
+class MyCircularDeque {
+public:
+    /** Initialize your data structure here. Set the size of the deque to be k. */
+    MyCircularDeque(int k) :
+        start_(0),
+        size_(0),
+        buffer_(k, 0) {
+        
+    }
+    
+    /** Adds an item at the front of Deque. Return true if the operation is successful. */
+    bool insertFront(int value) {
+        if (isFull()) {
+            return false;
+        }
+        start_ = (start_ - 1 + buffer_.size()) % buffer_.size();
+        buffer_[start_] = value;
+        ++size_;
+        return true;
+    }
+    
+    /** Adds an item at the rear of Deque. Return true if the operation is successful. */
+    bool insertLast(int value) {
+        if (isFull()) {
+            return false;
+        }
+        buffer_[(start_ + size_) % buffer_.size()] = value;
+        ++size_;
+        return true;
+    }
+    
+    /** Deletes an item from the front of Deque. Return true if the operation is successful. */
+    bool deleteFront() {
+        if (isEmpty()) {
+            return false;
+        }
+        start_ = (start_ + 1) % buffer_.size();
+        --size_;
+        return true;
+    }
+    
+    /** Deletes an item from the rear of Deque. Return true if the operation is successful. */
+    bool deleteLast() {
+        if (isEmpty()) {
+            return false;
+        }
+        --size_;
+        return true;
+    }
+    
+    /** Get the front item from the deque. */
+    int getFront() {
+        return isEmpty() ? -1 : buffer_[start_];
+    }
+    
+    /** Get the last item from the deque. */
+    int getRear() {
+        return isEmpty() ? -1 : buffer_[(start_ + size_ - 1) % buffer_.size()];
+    }
+    
+    /** Checks whether the circular deque is empty or not. */
+    bool isEmpty() {
+        return size_ == 0;
+    }
+    
+    /** Checks whether the circular deque is full or not. */
+    bool isFull() {
+        return size_ == buffer_.size();
+    }
+
+private:
+    int start_;
+    int size_;
+    vector<int> buffer_;
+};
+
+/**
+ * Your MyCircularDeque object will be instantiated and called as such:
+ * MyCircularDeque obj = new MyCircularDeque(k);
+ * bool param_1 = obj.insertFront(value);
+ * bool param_2 = obj.insertLast(value);
+ * bool param_3 = obj.deleteFront();
+ * bool param_4 = obj.deleteLast();
+ * int param_5 = obj.getFront();
+ * int param_6 = obj.getRear();
+ * bool param_7 = obj.isEmpty();
+ * bool param_8 = obj.isFull();
+ */
+