// CSE 143, Autumn 2016
//
// Practice with Stacks and Queues

import java.util.*;

public class Practice {
  public static void main(String[] args) {
    Queue<Integer> queue = new LinkedList<Integer>();
    Stack<Integer> stack = new Stack<Integer>();

    for (int i = 1; i <= 6; i++) {
      queue.add(i * 3);
      stack.push(i * 3);
    }

    /*System.out.println("Queue:");
    System.out.println("  numbers: " + queue);
    System.out.println("  sum: " + sum(queue));
    System.out.println("  numbers: " + queue);
    System.out.println();*/
    System.out.println("Stack:");
    System.out.println("  numbers: " + stack);
    System.out.println("  sum: " + sum(stack));
    System.out.println("  numbers: " + stack);
  }

  public static int sum(Queue<Integer> numbers) {
    int sum = 0;
    int size = numbers.size();
    for (int i = 0; i < size; i++) {
      int num = numbers.remove();
      numbers.add(num);
      sum += num;
    }
    return sum;
  }

  // can use one aux. Queue
  public static int sum(Stack<Integer> numbers) {
    int sum = 0;
    int size = numbers.size();
    Queue<Integer> temp = new LinkedList<Integer>();
    while (!numbers.isEmpty()) {
      int num = numbers.pop();
      temp.add(num);
      sum += num;
    }
    // we have sum, numbers empty, temp has all our data
    while (!temp.isEmpty()) {
      numbers.push(temp.remove());
    }
    while (!numbers.isEmpty()) {
      temp.add(numbers.pop());
    }
    while (!temp.isEmpty()) {
      numbers.push(temp.remove());
    }
    return sum;
  }
}