import java.util.*;

public class StackQueueClient {
   public static void main(String[] args) {
      // Make a queue with the numbers 1 through 5
      // Make an empty stack
      Queue<Integer> q = makeQueue();
      Stack<Integer> s = new Stack<>();
      
      System.out.println("initial q = " + q);
      System.out.println("initial s = " + s);
      System.out.println();
      
      // Sum up the queue
      System.out.println("sum of the queue");
      System.out.println("before");
      System.out.println("  q = " + q);
      int qSum = sum(q);
      System.out.println("after");
      System.out.println("  q = " + q);
      System.out.println("  sum = " + qSum);
      System.out.println();
      
      // Move everything from the queue to the stack
      System.out.println("queue to stack");
      System.out.println("before");
      System.out.println("  q = " + q);
      System.out.println("  s = " + s);
      queueToStack(q, s);
      System.out.println("after");
      System.out.println("  q = " + q);
      System.out.println("  s = " + s);
      System.out.println();
      
      // Sum up the stack
      System.out.println("sum of the stack");
      System.out.println("before");
      System.out.println("  s = " + s);
      int sSum = sum(s);
      System.out.println("after");
      System.out.println("  s = " + s);
      System.out.println("  sum = " + sSum);
   }
   
   public static Queue<Integer> makeQueue() {
      Queue<Integer> q = new LinkedList<>();
      for (int i = 1; i <= 5; i++) {
         q.add(i);
      }
      return q;
   }
   
   public static int sum(Queue<Integer> q) {
      int sum = 0;
      for (int i = 0; i < q.size(); i++) {
         int n = q.remove();
         sum += n;
         q.add(n);
      }
      return sum;
   }
   
   // pollev.com/cse143
   public static int sum(Stack<Integer> s) {
      int sum = 0;
      Queue<Integer> q = new LinkedList<>();
      int oldSize = s.size();  // need to save the old size!
      for (int i = 0; i < oldSize; i++) {  // or: while (!s.isEmpty()) {
         int n = s.pop();
         sum += n;
         q.add(n);
      }
      // put everything back in the stack and save order
      queueToStack(q, s);
      stackToQueue(s, q);
      queueToStack(q, s);
      return sum;
   }
   
   public static void queueToStack(Queue<Integer> q, Stack<Integer> s) {      
      while (!q.isEmpty()) {
         // Two line version
         // int n = q.remove();
         // s.push(n);
         
         // One line version
         s.push(q.remove());
      } 
   }
   
   public static void stackToQueue(Stack<Integer> s, Queue<Integer> q) {
      while (!s.isEmpty()) {
         // Two line version
         // int n = s.pop();
         // q.add(n);
         
         // One line version
         q.add(s.pop());
      }
   }
}