// Stuart Reges
// 10/18/06
//
// Program that demonstrates some simple stack/queue operations

import java.util.*;

public class StackQueue {
    public static void main(String[] args) {
        Queue<Integer> q = makeRandomQueue(10);
        System.out.println("initial queue = " + q);
        System.out.println("sum = " + sum(q));
        System.out.println("after sum queue = " + q);
	System.out.println();
        Stack<Integer> s = new ArrayStack<Integer>();
	queueToStack(q, s);
        System.out.println("after queueToStack:");
	System.out.println("    queue = " + q);
	System.out.println("    stack = " + s);
        System.out.println();
	s = makeRandomStack(10);
        System.out.println("initial stack = " + s);
        System.out.println("sum = " + sum(s));
        System.out.println("after sum stack = " + s);
	System.out.println();

	stackToQueue(s, q);
        System.out.println("after stackToQueue:");
	System.out.println("    stack = " + s);
	System.out.println("    queue = " + q);
    }

    // pre : size >= 0
    // post: returns a queue of size random values from 0 to 99
    public static Queue<Integer> makeRandomQueue(int size) {
        Random r = new Random();
        Queue<Integer> q = new LinkedQueue<Integer>();
        for (int i = 0; i < size; i++)
            q.enqueue(r.nextInt(100));
        return q;
    }

    // pre : size >= 0
    // post: returns a stack of size random values from 0 to 99
    public static Stack<Integer> makeRandomStack(int size) {
        Random r = new Random();
        Stack<Integer> s = new ArrayStack<Integer>();
        for (int i = 0; i < size; i++)
            s.push(r.nextInt(100));
        return s;
    }

    // post: Values from q moved to s (added in queue order, front to back);
    //       q is empty
    public static void queueToStack(Queue<Integer> q, Stack<Integer> s) {
        while (!q.isEmpty()) {
            int n = q.dequeue();
	    s.push(n);
	}
    }

    // post: Values from s moved to q (added in stack order, top to bottom);
    //       s is empty
    public static void stackToQueue(Stack<Integer> s, Queue<Integer> q) {
        while (!s.isEmpty()) {
            int n = s.pop();
	    q.enqueue(n);
	}
    }

    // post: Values from s moved to q (added in stack order, top to bottom);
    //       s is empty

    // post: returns the sum of the values in q
    public static int sum(Queue<Integer> q) {
        int sum = 0;
        for (int i = 0; i < q.size(); i++) {
            int n = q.dequeue();
            sum += n;
            q.enqueue(n);
        }
        return sum;
    }

    // post: returns the sum of the values in s
    public static int sum(Stack<Integer> s) {
        int sum = 0;
        Queue<Integer> q = new LinkedQueue<Integer>();
        while (!s.isEmpty()) {
            int n = s.pop();
            sum += n;
            q.enqueue(n);
        }
	queueToStack(q, s);
	stackToQueue(s, q);
	queueToStack(q, s);
        return sum;
    }
}