Minimum average of smallest and largest elements

#[test]
fn test_all_same() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![5, 5, 5, 5]);
    let expected = 5.0;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_all_same", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_example1() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![7, 8, 3, 4, 15, 13, 4, 1]);
    let expected = 5.5;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_example1", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_example2() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![1, 9, 8, 3, 10, 5]);
    let expected = 5.5;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_example2", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_example3() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![1, 2, 3, 7, 8, 9]);
    let expected = 5.0;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_example3", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_min_is_first_average() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![1, 2, 9, 10]);
    let expected = 5.5;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_min_is_first_average", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_sorted_ascending() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![1, 2, 3, 4]);
    let expected = 2.5;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_sorted_ascending", start, &expected, &val);
    assert!(pass);
}

#[test]
fn test_two_elements() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_average(vec![1, 3]);
    let expected = 2.0;
    let pass = (val - expected).abs() < 1e-9;
    log_result!(pass, "test_two_elements", start, &expected, &val);
    assert!(pass);
}