foundry_common/
calc.rs

1//! Commonly used calculations.
2
3/// Returns the mean of the slice.
4pub fn mean(values: &[u64]) -> u64 {
5    if values.is_empty() {
6        return 0;
7    }
8
9    (values.iter().map(|x| *x as u128).sum::<u128>() / values.len() as u128) as u64
10}
11
12/// Returns the median of a _sorted_ slice.
13pub fn median_sorted(values: &[u64]) -> u64 {
14    if values.is_empty() {
15        return 0;
16    }
17
18    let len = values.len();
19    let mid = len / 2;
20    if len.is_multiple_of(2) { (values[mid - 1] + values[mid]) / 2 } else { values[mid] }
21}
22
23#[cfg(test)]
24mod tests {
25    use super::*;
26
27    #[test]
28    fn calc_mean_empty() {
29        let m = mean(&[]);
30        assert_eq!(m, 0);
31    }
32
33    #[test]
34    fn calc_mean() {
35        let m = mean(&[0, 1, 2, 3, 4, 5, 6]);
36        assert_eq!(m, 3);
37    }
38
39    #[test]
40    fn calc_mean_overflow() {
41        let m = mean(&[0, 1, 2, u32::MAX as u64, 3, u16::MAX as u64, u64::MAX, 6]);
42        assert_eq!(m, 2305843009750573057);
43    }
44
45    #[test]
46    fn calc_median_empty() {
47        let m = median_sorted(&[]);
48        assert_eq!(m, 0);
49    }
50
51    #[test]
52    fn calc_median() {
53        let mut values = vec![29, 30, 31, 40, 59, 61, 71];
54        values.sort();
55        let m = median_sorted(&values);
56        assert_eq!(m, 40);
57    }
58
59    #[test]
60    fn calc_median_even() {
61        let mut values = vec![80, 90, 30, 40, 50, 60, 10, 20];
62        values.sort();
63        let m = median_sorted(&values);
64        assert_eq!(m, 45);
65    }
66}
foundry_common/calc.rs

foundry_common/
calc.rs
