ConditionsLoopsTask4DigitsSumCalculator.java

package HomeWorkSecond;

/**
 * Created by Andrey on 08.01.2016.
 */
public class ConditionsLoopsTask4DigitsSumCalculator {

    public static final int RADIX_TEN = 10;

    public static void main(String[] args) {
        int from = 10;
        int to = 12;
        System.out.print(digitSum(from, to));
    }

    public static int digitSum(int from, int to) {
        check(from, to);
        int temp = 0;
        for (int i = from; i <= to; i++) {
            temp += getSumLength(i);
        }
        temp = getAbs(temp);
        return temp;
    }

    public static int getAbs(int i) {
        int abs = Math.abs(i);
        return abs;
    }

    public static void check(int from, int to) {
        if (from > to) throw new IllegalArgumentException();
        return;
    }

    public static int getSumLength(int i) {
        i = getAbs(i);
        int sumLength = 0;
        while (i > 0) {
            int count = 0;
            int getSumLength = (i % RADIX_TEN);
            count += getSumLength;
            i /= RADIX_TEN;
            sumLength += count;
        }
        return sumLength;
    }

    public static int length(int i) {
        int length = 0;
        while (i > 0) {
            i = i / RADIX_TEN;
            length++;
        }
        return length;
    }
}