Multi-base primes: Difference between revisions
Content added Content deleted
Thundergnat (talk | contribs) (→{{header|Raku}}: Sorry, could not resist) |
(Added Rust solution) |
||
Line 186: | Line 186: | ||
5 character strings that are prime in maximum bases: 18 |
5 character strings that are prime in maximum bases: 18 |
||
30271 => [8 10 12 13 16 17 18 20 21 23 24 25 31 32 33 34 35 36]</pre> |
30271 => [8 10 12 13 16 17 18 20 21 23 24 25 31 32 33 34 35 36]</pre> |
||
=={{header|Rust}}== |
|||
{{trans|Julia}} |
|||
<lang rust>// [dependencies] |
|||
// primal = "0.3" |
|||
fn digits(mut n: u32, dig: &mut [u32]) { |
|||
for i in 0..dig.len() { |
|||
dig[i] = n % 10; |
|||
n /= 10; |
|||
} |
|||
} |
|||
fn evalpoly(x: u64, p: &[u32]) -> u64 { |
|||
let mut n = p.len(); |
|||
let mut result = 0; |
|||
while n > 0 { |
|||
n -= 1; |
|||
result *= x; |
|||
result += p[n] as u64; |
|||
} |
|||
result |
|||
} |
|||
fn max_prime_bases(ndig: u32, maxbase: u32) { |
|||
let mut maxlen = 0; |
|||
let mut maxprimebases = Vec::new(); |
|||
let limit = 10u32.pow(ndig); |
|||
let mut dig = vec![0; ndig as usize]; |
|||
for n in limit / 10..limit { |
|||
digits(n, &mut dig); |
|||
let bases: Vec<u32> = (2..=maxbase) |
|||
.filter(|&x| dig.iter().all(|&y| y < x) && primal::is_prime(evalpoly(x as u64, &dig))) |
|||
.collect(); |
|||
if bases.len() > maxlen { |
|||
maxlen = bases.len(); |
|||
maxprimebases.clear(); |
|||
} |
|||
if bases.len() == maxlen { |
|||
maxprimebases.push((n, bases)); |
|||
} |
|||
} |
|||
println!( |
|||
"{} character numeric strings that are prime in maximum bases: {}", |
|||
ndig, maxlen |
|||
); |
|||
for (n, bases) in maxprimebases { |
|||
println!("{} => {:?}", n, bases); |
|||
} |
|||
println!(); |
|||
} |
|||
fn main() { |
|||
for n in 1..=6 { |
|||
max_prime_bases(n, 36); |
|||
} |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
1 character numeric strings that are prime in maximum bases: 34 |
|||
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] |
|||
2 character numeric strings that are prime in maximum bases: 18 |
|||
21 => [3, 5, 6, 8, 9, 11, 14, 15, 18, 20, 21, 23, 26, 29, 30, 33, 35, 36] |
|||
3 character numeric strings that are prime in maximum bases: 18 |
|||
131 => [4, 5, 7, 8, 9, 10, 12, 14, 15, 18, 19, 20, 23, 25, 27, 29, 30, 34] |
|||
551 => [6, 7, 11, 13, 14, 15, 16, 17, 19, 21, 22, 24, 25, 26, 30, 32, 35, 36] |
|||
737 => [8, 9, 11, 12, 13, 15, 16, 17, 19, 22, 23, 24, 25, 26, 29, 30, 31, 36] |
|||
4 character numeric strings that are prime in maximum bases: 19 |
|||
1727 => [8, 9, 11, 12, 13, 15, 16, 17, 19, 20, 22, 23, 24, 26, 27, 29, 31, 33, 36] |
|||
5347 => [8, 9, 10, 11, 12, 13, 16, 18, 19, 22, 24, 25, 26, 30, 31, 32, 33, 34, 36] |
|||
5 character numeric strings that are prime in maximum bases: 18 |
|||
30271 => [8, 10, 12, 13, 16, 17, 18, 20, 21, 23, 24, 25, 31, 32, 33, 34, 35, 36] |
|||
6 character numeric strings that are prime in maximum bases: 18 |
|||
441431 => [5, 8, 9, 11, 12, 14, 16, 17, 19, 21, 22, 23, 26, 28, 30, 31, 32, 33] |
|||
</pre> |
|||
=={{header|Wren}}== |
=={{header|Wren}}== |