QueueOnStacks.java

package DailyCoding;

import java.util.Arrays;

/*this Program implements a simple Queue using two Stacks*/
public class QueueOnStacks
{/*this Program implements a simple Queue using two Stacks*/
    public static void main(String[] args)
    {
        QueueOnStacks qS = new QueueOnStacks();
        int[] nums = {1,2,3,4,5,6,7,8,9};
//        System.out.println(Arrays.toString(nums));
        for (int N:nums) qS.enqueue(N);


    }
    Stacks stack1; Stacks stack2;
//    public void enqueue(String val)
//    {/*adds elements to queue*/
//        //always enqueue into stack1
//        stack1.push(val);//add element to stack1
//    }
    public void enqueue(int val)
    {
        stack1.push(val);
    }
    public int dequeue()
    {/*removes element from queue*/
        //Always dequeue from stack2 as it contains first-IN values
        if(!stack2.isEmpty()){return stack2.pop();}//
        else//else if stack2 is empty;
            {//move all item in stack1 to stack2 then return the top element
                while (!stack1.isEmpty())
                {
                    stack2.push(stack1.pop());//remove values from stack1 to stack2 //this reverses the order to FIFO
                }
                return stack2.pop();
            }
    }
//    public String Show()
//    {//show values in queue
//    }
}