Find numbers with even number of digits

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::find_numbers(vec![12, 345, 2, 6, 7896]);
    let expected = 2;
    log_result!(val == expected, "t1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::find_numbers(vec![555, 901, 482, 1771]);
    let expected = 1;
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::find_numbers(vec![10, 100, 1000]);
    let expected = 2;
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::find_numbers(vec![1, 3, 5, 7, 9]);
    let expected = 0;
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::find_numbers(vec![10, 99, 100, 999]);
    let expected = 2;
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}