public class Solution
extends Object
2180 - Count Integers With Even Digit Sum\.
Easy
Given a positive integer `num`, return _the number of positive integers **less than or equal to**_ `num` _whose digit sums are **even**_.
The **digit sum** of a positive integer is the sum of all its digits.
**Example 1:**
**Input:** num = 4
**Output:** 2
**Explanation:**
The only integers less than or equal to 4 whose digit sums are even are 2 and 4.
**Example 2:**
**Input:** num = 30
**Output:** 14
**Explanation:**
The 14 integers less than or equal to 30 whose digit sums are even are
2, 4, 6, 8, 11, 13, 15, 17, 19, 20, 22, 24, 26, and 28.
**Constraints:**
* `1 <= num <= 1000`