Reddit Challenge 2014 04 14 Torn Number Java

Reddit20140414easy.java

// ** Puzzle;
// http://www.reddit.com/r/dailyprogrammer/comments/230m05/4142014_challenge_158_easy_the_torn_number/
// ** Algorithm;
// [3025] = (30+25)^2
// [abcd] = (ab+cd)^2
// 1000a + 100b + 10c + d = ( (10a + b) + (10c + d) )^2 
// ** Diff check; 
// a!=b & a!=c & a!=d & b!=c & b!=d & c!=d
// ** Output;
// Against the rule 'composed of four figures, all different': 2025
// Valid number found: 3025
// Valid number found: 9801
public class RedditChallenge {

    public static void main(String[] args) {
        try {
            //System.out.println("checkMonday(3025) : " + checkMonday(3025));
            challengeMonday();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void challengeMonday() {
        try {
            for (int i = 1000; i < 9999; i++) {
                if (checkMonday(i)) {
                    System.out.println("Valid number found: " + i);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static boolean checkMonday(int number) {
        try {
            String str = Integer.toString(number);
            if (str == null || str.isEmpty() || str.length() != 4) {
                return false;
            }

            // ABCD
            int digitA = Integer.parseInt("" + str.charAt(0)); // (number / 1000);
            int digitB = Integer.parseInt("" + str.charAt(1)); // (number / 100) % 10;
            int digitC = Integer.parseInt("" + str.charAt(2)); // (number / 10) % 10;
            int digitD = Integer.parseInt("" + str.charAt(3)); // (number % 10);

            int check = (1000 * digitA) + (100 * digitB) + (10 * digitC) + digitD;
            if (number != check) {
                System.out.println("Check number:" + number);
            }

            int result = ((10 * digitA + digitB) + (10 * digitC + digitD)) * ((10 * digitA + digitB) + (10 * digitC + digitD));
            if (result == number) {
                if (digitA == digitB || digitA == digitC || digitA == digitD
                        || digitB == digitC || digitB == digitD || digitC == digitD) {
                    System.out.println("Against the rule 'composed of four figures, all different': " + number);
                } else {
                    return true;
                }

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
}