# Count Integers With Even Digit Sum solution leetcode – Given a positive integer num, return the number of positive integers less than or equal to num whose digit sums are even.

Count Integers With Even Digit Sum solution leetcode – 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.

```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.
```

Given `head` which is a reference node to a singly-linked list. The value of each node in the linked list is either `0` or `1`. The linked list holds the binary representation of a number.

Return the decimal value of the number in the linked list.

## Count Integers With Even Digit Sum solution leetcode

```Input: head = [1,0,1]
Output: 5
Explanation: (101) in base 2 = (5) in base 10
```

## Count Integers With Even Digit Sum solution leetcode

```Input: head = [0]
Output: 0
```

Constraints:

• The Linked List is not empty.
• Number of nodes will not exceed `30`.
• Each node’s value is either `0` or `1`.