Solution To Reddit Daily Programmer Easy #243 - Abundant and Deficient Numbers

AbunDef.cs

using System;
using System.Collections;

//https://www.reddit.com/r/dailyprogrammer/comments/3uuhdk/20151130_challenge_243_easy_abundant_and/
//Reddit Daily Programmer Easy Challenge #243 - Abundant and Deficient Numbers

namespace AbunDef
{
    class Program
    {
        //Function to find divisors.
        public static ArrayList FindDivisors(int value)
        {
            ArrayList divisors = new ArrayList();

            for(int i = 1; i <= value; i++)
            {
                if(value % i == 0)
                {
                    divisors.Add(i);
                }
            }

            return divisors;
        }

        //Function to find proper divisors.
        public static ArrayList FindProperDivisors(int value)
        {
            ArrayList properDivisors = new ArrayList();

            for(int i = 1; i < value; i++)
            {
                if(value % i == 0)
                {
                    properDivisors.Add(i);
                }
            }

            return properDivisors;
        }

        //Function to sum an ArrayList.
        public static int SumArrayList(ArrayList divisorValues)
        {
            int sum = 0;

            foreach(int number in divisorValues)
            {
                sum += number;
            }

            return sum;
        }

        static void Main(string[] args)
        {
            //Numbers to check.
            int[] theNumbers = { 111, 112, 220, 69, 134, 85 };

            //Loop through them all, checking each.
            foreach (int theNumber in theNumbers)
            {
                //Check if it's an abundant number.
                int properSum = SumArrayList(FindProperDivisors(theNumber));

                if (properSum > theNumber)
                {
                    int difference = properSum - theNumber;
                    Console.WriteLine("{0} abundant by {1}", theNumber, difference);
                }
                else
                {
                    //Check if the number is deficient.
                    int divisorSum = SumArrayList(FindDivisors(theNumber));
                    if (divisorSum < (theNumber * 2))
                    {
                        Console.WriteLine("{0} deficient", theNumber);
                    }
                    else
                    {
                        Console.WriteLine("{0} ~~neither~~", theNumber);
                    }
                }
            }
        }
    }
}