Merge pull request #1759 from akgmage/dev

Dev

Author: akgmage

Stacks/stack_using_queue.cpp

@@ -1,4 +1,4 @@
-// stack using queue
+// stack using queues
 #include <iostream>
 #include <queue>
 

Stacks/stack_using_queue.go

@@ -1,4 +1,4 @@
-// stack using queue
+// stack using queues
 package main
 
 import (

Stacks/stack_using_queue.java

@@ -1,4 +1,4 @@
-// stack using queue
+// stack using queues
 import java.util.LinkedList;
 import java.util.Queue;
 

Stacks/stack_using_queue.js

@@ -0,0 +1,73 @@
+// Stack using queues
+class StackUsingQueues {
+  constructor() {
+    this.primaryQueue = [];
+    this.tempQueue = [];
+  }
+
+  // Push an element onto the stack.
+  push(x) {
+    // Add the element to the primary queue.
+    this.primaryQueue.push(x);
+  }
+
+  // Remove and return the top element of the stack.
+  pop() {
+    if (this.isEmpty()) {
+      throw new Error("Stack is empty");
+    }
+
+    // Move elements from the primary queue to the temporary queue except the last one.
+    while (this.primaryQueue.length > 1) {
+      this.tempQueue.push(this.primaryQueue.shift());
+    }
+
+    // Get the last element from the primary queue (top of the stack).
+    const topElement = this.primaryQueue.shift();
+
+    // Swap the primary and temporary queues.
+    [this.primaryQueue, this.tempQueue] = [this.tempQueue, this.primaryQueue];
+
+    return topElement;
+  }
+
+  // Return the top element of the stack without removing it.
+  top() {
+    if (this.isEmpty()) {
+      throw new Error("Stack is empty");
+    }
+
+    const topElement = this.pop();
+
+    // Add the top element back to the stack.
+    this.push(topElement);
+
+    return topElement;
+  }
+
+  // Check if the stack is empty.
+  isEmpty() {
+    return this.primaryQueue.length === 0;
+  }
+}
+
+const stack = new StackUsingQueues();
+
+// Push elements onto the stack.
+stack.push(1);
+stack.push(2);
+stack.push(3);
+
+// Pop elements from the stack.
+console.log(stack.pop()); // Output: 3
+console.log(stack.pop()); // Output: 2
+
+// Push more elements.
+stack.push(4);
+stack.push(5);
+
+// Peek at the top element.
+console.log(stack.top()); // Output: 5
+
+// Check if the stack is empty.
+console.log(stack.isEmpty()); // Output: false