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