// CSE 143, Winter 2011, Marty Stepp
//
// This program demonstrates the use of stacks and queues.
// It reads in a file of students' exam scores in reverse order, such as:
//
// Yeilding      Janet      87
// White         Steven     84
// Todd          Kim        52
// 
// And first strips the ones who got 100 on the exam using a queue,
// then prints the rest in reverse order using a stack.

import java.io.*;
import java.util.*;

public class Exams {
    public static void main(String[] args) throws FileNotFoundException {
        // read the lines from the file (in reverse ABC order) into a stack
        Scanner input = new Scanner(new File("exams.txt"));
        Stack<String> s = new Stack<String>();
        while (input.hasNextLine()) {
            String line = input.nextLine();  // "Todd          Kim        52"
            s.push(line);
        }
        
        // filter out the students who got 100 on the exam
        Queue<String> q = new LinkedList<String>();
        while (!s.isEmpty()) {
            String line = s.pop();
            if (!line.endsWith("100")) {
                q.add(line);
            }
        }
        
        // print all of the students' information in ABC order
        int size = q.size();
        for (int i = 0; i < size; i++) {
            String line = q.remove();
            System.out.println(line);
            q.add(line);
        }
        System.out.println(q);
        
        
        Stack<String> backup = new Stack<String>();
        while (!s.isEmpty()) {
            String line = s.pop();
            System.out.println(line);
            backup.push(line);
        }
        
//        System.out.println("Top students:");
//        while (!backup.isEmpty()) {
//            String line = backup.pop();
//            if (line.endsWith("100")) {
//                System.out.println(line);
//            }
//        }
        

        // Why it's usually bad to do a for loop from i=0 to size():
        // i       size 
        // 0       21
        // 1       20
        // 2       19
        // 3       18
        // 4       17
        // ...
        // 11      10
    }
}