// CSE 143, Winter 2011, Marty Stepp
// This program demonstrates the ArrayList class used with ints.
// You have to declare it as ArrayList<Integer> instead of <int>.
// Integer is a "wrapper" object around an int.

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

public class ProcessFile2 {
    public static void main(String[] args) throws FileNotFoundException {
        ArrayList<Integer> list = readFile("numbers.txt");
        System.out.println("Sum: " + sum(list));
        System.out.println("All elements : " + list);
        filterEvens(list);
        System.out.println("Without evens: " + list);
    }
    
    public static ArrayList<Integer> readFile(String fileName) throws FileNotFoundException {
        ArrayList<Integer> list = new ArrayList<Integer>();
        Scanner input = new Scanner(new File(fileName));
        while (input.hasNext()) {
            int num = input.nextInt();
            list.add(num);
        }
        return list;
    }
    
    // Returns the sum of all the elements in the list.
    public static int sum(ArrayList<Integer> list) {
        int sum = 0;
        for (int i = list.size() - 1; i >= 0; i--) {
            int num = list.get(i);
            sum += num;
        }
        return sum;
    }

    // Removes any even numbers from the given array list.
    public static void filterEvens(ArrayList<Integer> list) {
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i) % 2 == 0) {
                list.remove(i);
                i--;  // needed in case there are consecutive even numbers
            }
        }
    }
}