Maximum average subarray i

#[test]
fn t1() {
    let s = std::time::Instant::now();
    let v = Solution::find_max_average(vec![1,12,-5,-6,50,3], 4);
    log_result!((v - 12.75).abs() < 1e-5, "t1", s, 12.75, v);
    assert!((v - 12.75).abs() < 1e-5);
}

#[test]
fn t2() {
    let s = std::time::Instant::now();
    let v = Solution::find_max_average(vec![5], 1);
    log_result!((v - 5.0).abs() < 1e-5, "t2", s, 5.0, v);
    assert!((v - 5.0).abs() < 1e-5);
}

#[test]
fn t3() {
    let s = std::time::Instant::now();
    let v = Solution::find_max_average(vec![-1,-2,-3,-4], 2);
    log_result!((v - (-1.5)).abs() < 1e-5, "t3", s, -1.5, v);
    assert!((v - (-1.5)).abs() < 1e-5);
}

#[test]
fn t4() {
    let s = std::time::Instant::now();
    let v = Solution::find_max_average(vec![0,1,1,3,3], 4);
    log_result!((v - 2.0).abs() < 1e-5, "t4", s, 2.0, v);
    assert!((v - 2.0).abs() < 1e-5);
}

#[test]
fn t5() {
    let s = std::time::Instant::now();
    let v = Solution::find_max_average(vec![4,0,4,3,3], 5);
    log_result!((v - 2.8).abs() < 1e-5, "t5", s, 2.8, v);
    assert!((v - 2.8).abs() < 1e-5);
}