Java Program for Difference between sums of odd and even digits

Write a java program for a given long integer, the task is to find if the difference between sum of odd digits and sum of even digits is 0 or not. The indexes start from zero (0 index is for leftmost digit).

Examples:

Input : 1212112
Output : Yes
Explanation:
the odd position element is 2+2+1=5
the even position element is 1+1+1+2=5
the difference is 5-5=0 equal to zero.
So print yes.

Input :12345
Output : No
Explanation:
the odd position element is 1+3+5=9
the even position element is 2+4=6
the difference is 9-6=3 not equal to zero.
So print no.

Approach:

One by one traverse digits and find the two sums. If difference between two sums is 0, print yes, else no. 

Below is the implementation of the above approach:

Java

// Java equivalent of above code
public class Main {
    // Function to check if the difference between the sum
    // of alternating digits in 'n' is 0
    public static boolean isDiff0(int n)
    {
        // Variable to store the sum of alternating digits
        int first = 0;
        // Variable to store the sum of the other
        // alternating digits
        int second = 0;
        // A flag to alternate between 'first' and 'second'
        // sums
        boolean flag = true;
        // Extract the last digit from 'n'
        while (n > 0) {
            int digit = n % 10;
            // Add 'digit' to 'first' if 'flag' is true
            if (flag) {
                first += digit;
            }
            // Add 'digit' to 'second' if 'flag' is false
            else {
                second += digit;
            }
            // Toggle the flag for the next digit
            flag = !flag;
            // Remove the last digit from 'n'
            n = n / 10;
        }

        if (first - second == 0) {
            // Return true if the difference between 'first'
            // and 'second'sums is 0
            return true;
        }
        // Otherwise, return false
        return false;
    }

    public static void main(String[] args)
    {
        // The input number
        int n = 1243;
        // If isDiff0 returns true, print "Yes"
        if (isDiff0(n)) {
            System.out.println("Yes");
        }
        // If isDiff0 returns false, print "No"
        else {
            System.out.println("No");
        }
    }
}

Output

Yes

Time Complexity:O(log n)
Auxiliary space: O(1)

Please refer complete article on Difference between sums of odd and even digits for more details!