// Zorah Fung, CSE 143
// Demonstrates basic stack and queue manipulations

import java.util.*;

public class StackQueueSum {
    public static void main(String[] args) {
        Queue<Integer> q = fillQueue(10);
        Stack<Integer> s = fillStack(10);

        System.out.println("initial queue: " + q);
        System.out.println("sum = " + queueSum(q));
        System.out.println("queue: " + q);
        System.out.println();
        System.out.println("initial stack: " + s);
        System.out.println("sum = " + stackSum(s));
        System.out.println("stack: " + s);
    }

    // Creates and returns a queue with the values 1 - n (front to back)
    // Pre: n >= 1;
    public static Queue<Integer> fillQueue(int n) {
        Queue<Integer> q = new LinkedList<Integer>();
        for (int i = 1; i <= n; i++) {
            q.add(i);
        }
        return q;
    }

    // Creates and returns a stack with the values 1 - n (bottom to top)
    // Pre: n >= 1;
    public static Stack<Integer> fillStack(int n) {
        Stack<Integer> s = new Stack<Integer>();
        for (int i = 1; i <= n; i++) {
            s.push(i);
        }
        return s;
    }

    // Returns the sum of the values of the given queue
    public static int queueSum(Queue<Integer> q) {
        int sum = 0;
        for (int i = 0; i < q.size(); i++) {
            int num = q.remove();
            sum += num;
            q.add(num);
        }
        return sum;
    }

    // Returns the sum of the values of the given stack
    public static int stackSum(Stack<Integer> s) {
        int sum = 0;
        Queue<Integer> q = new LinkedList<Integer>();
        while (!s.isEmpty()) {
            int num = s.pop();
            sum += num;
            q.add(num);
        }
        queueToStack(q, s);
        stackToQueue(s, q);
        queueToStack(q, s);
        return sum;
    }

    // Transfers all the values from the given queue to the given stack
    public static void queueToStack(Queue<Integer> q, Stack<Integer> s) {
        while (!q.isEmpty()) {
            s.push(q.remove());
        }
    }

    // Transfers all the values from the given stack to the given queue
    public static void stackToQueue(Stack<Integer> s, Queue<Integer> q) {
        while (!s.isEmpty()) {
            q.add(s.pop());
        }
    }
}