Create 0225-implement-stack-using-queues.js

Author: AP-Repositories

javascript/0225-implement-stack-using-queues.js

@@ -0,0 +1,27 @@
+var MyStack = function() {
+    this.q = [];
+};
+
+MyStack.prototype.push = function(x) {
+    this.q.push(x);
+};
+
+MyStack.prototype.pop = function() {
+    let size = this.q.length;
+    for(let i = 0; i < size - 1; i++)
+        this.push(this.q.shift());
+    return this.q.shift();
+};
+
+MyStack.prototype.top = function() {
+    let size = this.q.length;
+    for(let i = 0; i < size - 1; i++)
+        this.push(this.q.shift());
+    let res = this.q.shift();
+    this.push(res);
+    return res;
+};
+
+MyStack.prototype.empty = function() {
+    return this.q.length == 0
+};