package mode.problem;

import java.util.*;

/**
 *
 * @author Daniel Ruess <mistermaggot@gmail.com>
 */
public class ModeProblem {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        List<Integer> nums = new ArrayList<Integer>();
        Scanner in = new Scanner(System.in);
        while (true) {
            System.out.print("Enter a number (enter M to find the mode): ");
            String n = in.next();
            if (n.equalsIgnoreCase("M")) {
                int[] mode = findMode(nums);
                System.out.println("The mode of the number set is " + mode[0] + " with a frequency of " + mode[1]);
                return;
            } else {
                for (char c : n.toCharArray()) {
                    if (!Character.isDigit(c)) {
                        System.err.println("Invalid input: " + n);
                        return;
                    }
                }
                nums.add(Integer.valueOf(n));
            }
        }
    }
    
    static int[] findMode(List<Integer> vals) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();
        for (Integer i : vals) {
            if (map.get(i) == null) {
                map.put(i, 1);
            } else {
                map.put(i, map.get(i) + 1);
            }
        }
        int mode = -1, v = 0;
        for (Integer i : map.keySet()) {
            if (map.get(i) > v) {
                mode = i;
                v = map.get(i);
            }
        }
        return new int[] { mode, v };
    }
}