solve 641.design-circular-deque

Author: andavid

vscode/641.design-circular-deque.java

@@ -0,0 +1,159 @@
+/*
+ * @lc app=leetcode id=641 lang=java
+ *
+ * [641] Design Circular Deque
+ *
+ * https://leetcode.com/problems/design-circular-deque/description/
+ *
+ * algorithms
+ * Medium (48.68%)
+ * Likes:    120
+ * Dislikes: 30
+ * Total Accepted:    8.5K
+ * Total Submissions: 17.1K
+ * Testcase Example:  '["MyCircularDeque","insertLast","insertLast","insertFront","insertFront","getRear","isFull","deleteLast","insertFront","getFront"]\n[[3],[1],[2],[3],[4],[],[],[],[4],[]]'
+ *
+ * Design your implementation of the circular double-ended queue (deque).
+ *
+ * Your implementation should support following operations:
+ *
+ *
+ * MyCircularDeque(k): Constructor, set the size of the deque to be k.
+ * insertFront(): Adds an item at the front of Deque. Return true if the
+ * operation is successful.
+ * insertLast(): Adds an item at the rear of Deque. Return true if the
+ * operation is successful.
+ * deleteFront(): Deletes an item from the front of Deque. Return true if the
+ * operation is successful.
+ * deleteLast(): Deletes an item from the rear of Deque. Return true if the
+ * operation is successful.
+ * getFront(): Gets the front item from the Deque. If the deque is empty,
+ * return -1.
+ * getRear(): Gets the last item from Deque. If the deque is empty, return
+ * -1.
+ * isEmpty(): Checks whether Deque is empty or not. 
+ * isFull(): Checks whether Deque is full or not.
+ *
+ *
+ *
+ *
+ * Example:
+ *
+ *
+ * MyCircularDeque circularDeque = new MycircularDeque(3); // set the size to
+ * be 3
+ * circularDeque.insertLast(1);            // return true
+ * circularDeque.insertLast(2);            // return true
+ * circularDeque.insertFront(3);            // return true
+ * circularDeque.insertFront(4);            // return false, the queue is full
+ * circularDeque.getRear();              // return 2
+ * circularDeque.isFull();                // return true
+ * circularDeque.deleteLast();            // return true
+ * circularDeque.insertFront(4);            // return true
+ * circularDeque.getFront();            // return 4
+ *
+ *
+ *
+ *
+ * Note:
+ *
+ *
+ * All values will be in the range of [0, 1000].
+ * The number of operations will be in the range of [1, 1000].
+ * Please do not use the built-in Deque library.
+ *
+ *
+ */
+class MyCircularDeque {
+
+  private int[] data;
+  private int head;
+  private int tail;
+  private int size;
+
+  /** Initialize your data structure here. Set the size of the deque to be k. */
+  public MyCircularDeque(int k) {
+    data = new int[k + 1];
+    size = k + 1;
+    head = 0;
+    tail = 0;
+  }
+
+  /** Adds an item at the front of Deque. Return true if the operation is successful. */
+  public boolean insertFront(int value) {
+    if (isFull()) {
+      return false;
+    }
+    head = (head - 1 + size) % size;
+    data[head] = value;
+    return true;
+  }
+
+  /** Adds an item at the rear of Deque. Return true if the operation is successful. */
+  public boolean insertLast(int value) {
+    if (isFull()) {
+      return false;
+    }
+    data[tail] = value;
+    tail = (tail + 1) % size;
+    return true;
+  }
+
+  /** Deletes an item from the front of Deque. Return true if the operation is successful. */
+  public boolean deleteFront() {
+    if (isEmpty()) {
+      return false;
+    }
+    head = (head + 1) % size;
+    return true;
+  }
+
+  /** Deletes an item from the rear of Deque. Return true if the operation is successful. */
+  public boolean deleteLast() {
+    if (isEmpty()) {
+      return false;
+    }
+    tail = (tail - 1 + size) % size;
+    return true;
+  }
+
+  /** Get the front item from the deque. */
+  public int getFront() {
+    if (isEmpty()) {
+      return -1;
+    }
+    return data[head];
+  }
+
+  /** Get the last item from the deque. */
+  public int getRear() {
+    if (isEmpty()) {
+      return -1;
+    }
+    return data[(tail - 1 + size) % size];
+  }
+
+  /** Checks whether the circular deque is empty or not. */
+  public boolean isEmpty() {
+    return head == tail;
+  }
+
+  /** Checks whether the circular deque is full or not. */
+  public boolean isFull() {
+    return (tail + 1) % size == head;
+  }
+}
+
+/**
+ * Your MyCircularDeque object will be instantiated and called as such:
+ * MyCircularDeque obj = new MyCircularDeque(k);
+ * boolean param_1 = obj.insertFront(value);
+ * boolean param_2 = obj.insertLast(value);
+ * boolean param_3 = obj.deleteFront();
+ * boolean param_4 = obj.deleteLast();
+ * int param_5 = obj.getFront();
+ * int param_6 = obj.getRear();
+ * boolean param_7 = obj.isEmpty();
+ * boolean param_8 = obj.isFull();
+ */
+