Create Stack-Implement-using-Queues.java

src/Stack-Implement-using-Queues.java

@@ -0,0 +1,63 @@
+import java.util.LinkedList;
+import java.util.Queue;
+
+class StackUsingQueues {
+    private Queue<Integer> queue1 = new LinkedList<>();
+    private Queue<Integer> queue2 = new LinkedList<>();
+    private int top;
+
+    /** Initialize your data structure here. */
+    public StackUsingQueues() {
+        // Constructor: Initialize the two queues and top element.
+    }
+
+    /** Push element x onto the stack. */
+    public void push(int x) {
+        // Add the new element to an empty queue (queue1).
+        queue1.add(x);
+        // Update the top element.
+        top = x;
+        // Transfer elements from queue2 to queue1.
+        while (!queue2.isEmpty()) {
+            queue1.add(queue2.poll());
+        }
+        // Swap the names of queue1 and queue2 to maintain consistency.
+        Queue<Integer> temp = queue1;
+        queue1 = queue2;
+        queue2 = temp;
+    }
+
+    /** Removes the element on the top of the stack and returns that element. */
+    public int pop() {
+        // Pop operation is equivalent to removing the top element from queue2.
+        int popped = queue2.poll();
+        // If queue2 is empty, update the top element to the new top.
+        if (!queue2.isEmpty()) {
+            top = queue2.peek();
+        }
+        return popped;
+    }
+
+    /** Get the top element. */
+    public int top() {
+        return top;
+    }
+
+    /** Returns whether the stack is empty. */
+    public boolean empty() {
+        return queue2.isEmpty();
+    }
+
+    public static void main(String[] args) {
+        StackUsingQueues stack = new StackUsingQueues();
+
+        stack.push(1);
+        stack.push(2);
+        System.out.println("Top element: " + stack.top()); // Output: 2
+        System.out.println("Is the stack empty? " + stack.empty()); // Output: false
+
+        stack.pop();
+        System.out.println("Top element after pop: " + stack.top()); // Output: 1
+        System.out.println("Is the stack empty? " + stack.empty()); // Output: false
+    }
+}