// Helene Martin, CSE 143
// Basic problems using stack/queue traversals.

import java.util.*;

public class StacksQueues {
   public static void main(String[] args) {
      Stack<Integer> nums = createRandomStack(12);
      System.out.println("Random stack: " + nums);
      int max = max(nums);
      System.out.println("Max: " + max);
      System.out.println("Stack after max: " + nums);
      System.out.println();

      Queue<Integer> q = createRandomQueue(12);
      System.out.println("Random queue: " + q);
      int sum = sum(q);
      System.out.println("Sum " + sum);
      System.out.println("Queue after sum: " + q);
   }

   // Returns the max of values in a stack of integers.
   // Post: stack is unchanged.
   // (We thought about saving the values in a temp queue but noticed
   // that would reverse their order.)
   public static int max(Stack<Integer> nums) {
      int max = 0;
      Stack<Integer> temp = new Stack<Integer>();

      while (!nums.isEmpty()) {
         int value = nums.pop();
         temp.push(value);
         if (value > max) {
            max = value;
         }
      }

      // restore the original stack
      while (!temp.isEmpty()) {
         nums.push(temp.pop());
      }
      return max;
   }

   // Returns the sum of all values in a queue of integers.
   // Post: queue is unchanged
   public static int sum(Queue<Integer> q) {
      int sum = 0;

      int size = q.size();
      for (int i = 0; i < size; i++) {
         int value = q.remove();
         sum += value;
         q.add(value); // save values directly back to the queue
      }

      return sum;
   }

   // Creates and returns a stack with the specified number of random values
   // in the range 0-29.
   public static Stack<Integer> createRandomStack(int size) {
      Stack<Integer> nums = new Stack<Integer>();
      Random r = new Random();
      for (int i = 0; i < size; i++) {
         nums.push(r.nextInt(30));
      }
      return nums;
   }

   // Creates and returns a queue with the specified number of random values
   // in the range 0-29.
   public static Queue<Integer> createRandomQueue(int size) {
      Queue<Integer> q = new LinkedList<Integer>();
      Random r = new Random();
      for (int i = 0; i < size; i++) {
         q.add(r.nextInt(30));
      }
      return q;
   }
}