| pub struct MovingAverage { |
| len: usize, |
| values: Vec::<u64>, |
| current_index: usize, |
| weights: Vec::<u64>, |
| weights_total: u64, |
| } |
|
|
| impl MovingAverage { |
| pub fn new() -> Self { |
| let len = 19; |
| let weights = vec![ |
| 8, 16, 32, 64, 80, 85, 90, 95, |
| 100, |
| 100, |
| 100, |
| 95, 90, 85, 80, 64, 32, 16, 8 |
| ]; |
| let mut weight_total = 0; |
| for v in &weights { |
| weight_total += v; |
| } |
| Self { |
| len: len, |
| values: vec![0; len], |
| current_index: 0, |
| weights: weights, |
| weights_total: weight_total |
| } |
| } |
|
|
| pub fn insert(&mut self, value: u64) { |
| self.values[self.current_index] = value; |
| } |
|
|
| pub fn average(&self) -> u64 { |
| let mut sum: u64 = 0; |
| for i in 0..self.len { |
| let offset = (self.current_index + i) % self.len; |
| let weight = self.weights[offset]; |
| let value = self.values[offset]; |
| sum += value * weight; |
| } |
| sum / self.weights_total |
| } |
|
|
| pub fn rotate(&mut self) { |
| self.current_index = (self.current_index + 1) % self.len; |
| } |
| } |
|
|
| #[cfg(test)] |
| mod tests { |
| use super::*; |
|
|
| #[test] |
| fn test_10000_all_zeroes() { |
| let instance = MovingAverage::new(); |
| assert_eq!(instance.average(), 0); |
| } |
|
|
| #[test] |
| fn test_10001_all_some_value() { |
| let mut instance = MovingAverage::new(); |
| for _ in 0..20 { |
| instance.insert(1000); |
| instance.rotate(); |
| } |
| assert_eq!(instance.average(), 1000); |
| } |
|
|
| #[test] |
| fn test_10002_half_some_value_half_zeroes() { |
| let mut instance = MovingAverage::new(); |
| for _ in 0..10 { |
| instance.insert(1000); |
| instance.rotate(); |
| } |
| assert_eq!(instance.average(), 540); |
| } |
| } |
|
|
