Difference Between Element Sum and Digit Sum of an Array
<p>You are given a positive integer array <code>nums</code>.</p>

<ul>
	<li>The <strong>element sum</strong> is the sum of all the elements in <code>nums</code>.</li>
	<li>The <strong>digit sum</strong> is the sum of all the digits (not necessarily distinct) that appear in <code>nums</code>.</li>
</ul>

<p>Return <em>the <strong>absolute</strong> difference between the <strong>element sum</strong> and <strong>digit sum</strong> of </em><code>nums</code>.</p>

<p><strong>Note</strong> that the absolute difference between two integers <code>x</code> and <code>y</code> is defined as <code>|x - y|</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,15,6,3]
<strong>Output:</strong> 9
<strong>Explanation:</strong> 
The element sum of nums is 1 + 15 + 6 + 3 = 25.
The digit sum of nums is 1 + 1 + 5 + 6 + 3 = 16.
The absolute difference between the element sum and digit sum is |25 - 16| = 9.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4]
<strong>Output:</strong> 0
<strong>Explanation:</strong>
The element sum of nums is 1 + 2 + 3 + 4 = 10.
The digit sum of nums is 1 + 2 + 3 + 4 = 10.
The absolute difference between the element sum and digit sum is |10 - 10| = 0.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 2000</code></li>
</ul>
Array; Math
class Solution {
    public int differenceOfSum(int[] nums) {
        int x = 0, y = 0;
        for (int v : nums) {
            x += v;
            for (; v > 0; v /= 10) {
                y += v % 10;
            }
        }
        return x - y;
    }
}
