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-rw-r--r--rust/sieve/src/lib.rs16
1 files changed, 16 insertions, 0 deletions
diff --git a/rust/sieve/src/lib.rs b/rust/sieve/src/lib.rs
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+++ b/rust/sieve/src/lib.rs
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1pub fn primes_up_to(upper_bound: u64) -> Vec<u64> {
2 let mut sieve: Vec<Option<u64>> = (2..=upper_bound).map(Some).collect();
3 primes(&mut sieve);
4 sieve.iter().filter_map(|x| *x).collect()
5}
6
7fn primes(ps: &mut [Option<u64>]) {
8 if let Some(&n) = ps.first() {
9 if let Some(p) = n {
10 (p as usize..ps.len())
11 .step_by(p as usize)
12 .for_each(|x| ps[x] = None)
13 }
14 primes(&mut ps[1..]);
15 }
16}