Maximum difference between adjacent elements in a circular array

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::max_adjacent_distance(vec![1, 2, 4]);
    let expected = 3;
    log_result!(val == expected, "t1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::max_adjacent_distance(vec![-5, -10, -5]);
    let expected = 5;
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::max_adjacent_distance(vec![1, 1, 1, 1]);
    let expected = 0;
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::max_adjacent_distance(vec![10, -10]);
    let expected = 20;
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::max_adjacent_distance(vec![1, 3, 6, 10, 15]);
    let expected = 14;
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}