forked from tikv/pprof-rs
-
Notifications
You must be signed in to change notification settings - Fork 0
/
prime_number.rs
63 lines (53 loc) · 1.43 KB
/
prime_number.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
#[inline(never)]
fn is_prime_number(v: usize, prime_numbers: &[usize]) -> bool {
if v < 10000 {
let r = prime_numbers.binary_search(&v);
return r.is_ok();
}
for n in prime_numbers {
if v % n == 0 {
return false;
}
}
true
}
#[inline(never)]
fn prepare_prime_numbers() -> Vec<usize> {
// bootstrap: Generate a prime table of 0..10000
let mut prime_number_table: [bool; 10000] = [true; 10000];
prime_number_table[0] = false;
prime_number_table[1] = false;
for i in 2..10000 {
if prime_number_table[i] {
let mut v = i * 2;
while v < 10000 {
prime_number_table[v] = false;
v += i;
}
}
}
let mut prime_numbers = vec![];
for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
if *exist {
prime_numbers.push(i);
}
}
prime_numbers
}
fn main() {
let prime_numbers = prepare_prime_numbers();
let guard = pprof::ProfilerGuard::new(100).unwrap();
loop {
let mut v = 0;
for i in 2..50000 {
if is_prime_number(i, &prime_numbers) {
v += 1;
}
}
println!("Prime numbers: {}", v);
if let Ok(report) = guard.report().build() {
println!("{:?}", report);
};
}
}