Add solution #641

Author: JoshCrozier

0641-design-circular-deque.js

@@ -0,0 +1,106 @@
+/**
+ * 641. Design Circular Deque
+ * https://leetcode.com/problems/design-circular-deque/
+ * Difficulty: Medium
+ *
+ * Design your implementation of the circular double-ended queue (deque).
+ *
+ * Implement the MyCircularDeque class:
+ * - MyCircularDeque(int k) Initializes the deque with a maximum size of k.
+ * - boolean insertFront() Adds an item at the front of Deque. Returns true if the operation
+ *   is successful, or false otherwise.
+ * - boolean insertLast() Adds an item at the rear of Deque. Returns true if the operation
+ *   is successful, or false otherwise.
+ * - boolean deleteFront() Deletes an item from the front of Deque. Returns true if the
+ *   operation is successful, or false otherwise.
+ * - boolean deleteLast() Deletes an item from the rear of Deque. Returns true if the operation
+ *   is successful, or false otherwise.
+ * - int getFront() Returns the front item from the Deque. Returns -1 if the deque is empty.
+ * - int getRear() Returns the last item from Deque. Returns -1 if the deque is empty.
+ * - boolean isEmpty() Returns true if the deque is empty, or false otherwise.
+ * - boolean isFull() Returns true if the deque is full, or false otherwise.
+ */
+
+/**
+ * @param {number} k
+ */
+var MyCircularDeque = function(k) {
+  this.queue = new Array(k);
+  this.size = k;
+  this.front = 0;
+  this.rear = -1;
+  this.count = 0;
+};
+
+/**
+ * @param {number} value
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.insertFront = function(value) {
+  if (this.isFull()) return false;
+  this.front = (this.front - 1 + this.size) % this.size;
+  this.queue[this.front] = value;
+  this.count++;
+  if (this.count === 1) this.rear = this.front;
+  return true;
+};
+
+/**
+ * @param {number} value
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.insertLast = function(value) {
+  if (this.isFull()) return false;
+  this.rear = (this.rear + 1) % this.size;
+  this.queue[this.rear] = value;
+  this.count++;
+  return true;
+};
+
+/**
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.deleteFront = function() {
+  if (this.isEmpty()) return false;
+  this.front = (this.front + 1) % this.size;
+  this.count--;
+  return true;
+};
+
+/**
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.deleteLast = function() {
+  if (this.isEmpty()) return false;
+  this.rear = (this.rear - 1 + this.size) % this.size;
+  this.count--;
+  return true;
+};
+
+/**
+ * @return {number}
+ */
+MyCircularDeque.prototype.getFront = function() {
+  return this.isEmpty() ? -1 : this.queue[this.front];
+};
+
+/**
+ * @return {number}
+ */
+MyCircularDeque.prototype.getRear = function() {
+  return this.isEmpty() ? -1 : this.queue[this.rear];
+};
+
+/**
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.isEmpty = function() {
+  return this.count === 0;
+};
+
+/**
+ * @return {boolean}
+ */
+MyCircularDeque.prototype.isFull = function() {
+  return this.count === this.size;
+};

README.md

@@ -482,6 +482,7 @@
 637|[Average of Levels in Binary Tree](./0637-average-of-levels-in-binary-tree.js)|Easy|
 638|[Shopping Offers](./0638-shopping-offers.js)|Medium|
 639|[Decode Ways II](./0639-decode-ways-ii.js)|Hard|
+641|[Design Circular Deque](./0641-design-circular-deque.js)|Medium|
 643|[Maximum Average Subarray I](./0643-maximum-average-subarray-i.js)|Easy|
 645|[Set Mismatch](./0645-set-mismatch.js)|Medium|
 648|[Replace Words](./0648-replace-words.js)|Medium|