Stack Using Queues in Java: Explanation & Practice

Problem summary

Create a Stack class that internally uses only Queue operations.

Starter code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        // Implement stack using queues
        // push(1), push(2), push(3)
        // pop() should return 3
        // Print: Popped: <value>
    }
}

Expected output and test cases

• LIFO behavior

  Popped: 3

• After more pushes

  Popped: 5

• Single element

  Popped: 1

Hints

1. Use two queues
2. On push, add to empty queue
3. Move all from other queue

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