Create 0232-implement-queue-using-stacks.js

Author: nikkikharkwal

javascript/0232-implement-queue-using-stacks.js

@@ -0,0 +1,57 @@
+// https://leetcode.com/problems/implement-queue-using-stacks/
+
+var MyQueue = function() {
+    this.stack1 = [];
+    this.stack2 = []; 
+};
+
+/** 
+ * @param {number} x
+ * @return {void}
+ */
+MyQueue.prototype.push = function(x) {
+    this.stack1.push(x);
+};
+
+/**
+ * @return {number}
+ */
+MyQueue.prototype.pop = function() {
+    this.swappingStacks();
+    
+    if(!this.stack2.length){
+        return null;
+    }
+    return this.stack2.pop();
+};
+
+/**
+ * @return {number}
+ */
+MyQueue.prototype.peek = function() {
+    this.swappingStacks();
+    return this.stack2.length == 0 ? null : this.stack2[this.stack2.length-1]
+};
+
+/**
+ * @return {boolean}
+ */
+MyQueue.prototype.empty = function() {
+    return this.stack1.length === 0 && this.stack2.length === 0;
+};
+
+MyQueue.prototype.swappingStacks = function() {
+    if (this.stack1.length) {
+        this.stack2 = [...this.stack1.reverse(), ...this.stack2];
+        this.stack1 = [];
+    }
+}
+
+/** 
+ * Your MyQueue object will be instantiated and called as such:
+ * var obj = new MyQueue()
+ * obj.push(x)
+ * var param_2 = obj.pop()
+ * var param_3 = obj.peek()
+ * var param_4 = obj.empty()
+ */