1295. Find Numbers with Even Number of Digits

Input: nums = [12,345,2,6,7896]
Output: 2
Explanation: 
12 contains 2 digits (even number of digits). 
345 contains 3 digits (odd number of digits). 
2 contains 1 digit (odd number of digits). 
6 contains 1 digit (odd number of digits). 
7896 contains 4 digits (even number of digits). 
Therefore only 12 and 7896 contain an even number of digits.

Input: nums = [555,901,482,1771]
Output: 1 
Explanation: 
Only 1771 contains an even number of digits.

Rust Solution

struct Solution;

impl Solution {
    fn digits(mut n: i32) -> i32 {
        let mut res = 0;
        while n != 0 {
            n /= 10;
            res += 1;
        }
        res
    }
    fn find_numbers(nums: Vec<i32>) -> i32 {
        let mut res = 0;
        for n in nums {
            if Self::digits(n) % 2 == 0 {
                res += 1;
            }
        }
        res
    }
}

#[test]
fn test() {
    assert_eq!(Solution::find_numbers(vec![12, 345, 2, 6, 7896]), 2);
}