Magic numbers: Difference between revisions
Added Rust solution
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All magic numbers that are pan-digital in 0 through 9 with no repeats: 3816547290</pre>
=={{header|Rust}}==
<syntaxhighlight lang="rust">fn get_digits(mut n: u128) -> [usize; 10] {
let mut digits = [0; 10];
while n > 0 {
digits[(n % 10) as usize] += 1;
n /= 10;
}
digits
}
fn magic_numbers() -> impl std::iter::Iterator<Item = u128> {
let mut magic: Vec<u128> = vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
let mut index = 0;
let mut digits = 2;
std::iter::from_fn(move || {
if index == magic.len() {
let mut magic_new: Vec<u128> = Vec::new();
for &m in &magic {
if m == 0 {
continue;
}
let mut n = 10 * m;
for _ in 0..10 {
if n % digits == 0 {
magic_new.push(n);
}
n += 1;
}
}
index = 0;
digits += 1;
magic = magic_new;
}
if magic.is_empty() {
return None;
}
let m = magic[index];
index += 1;
Some(m)
})
}
fn main() {
let mut count = 0;
let mut dcount = 0;
let mut magic: u128 = 0;
let mut p: u128 = 10;
let digits0 = [1; 10];
let digits1 = [0, 1, 1, 1, 1, 1, 1, 1, 1, 1];
let mut pandigital0: Vec<u128> = Vec::new();
let mut pandigital1: Vec<u128> = Vec::new();
let mut digit_count: Vec<usize> = Vec::new();
for m in magic_numbers() {
magic = m;
if magic >= p {
p *= 10;
digit_count.push(dcount);
dcount = 0;
}
let digits = get_digits(magic);
if digits == digits0 {
pandigital0.push(magic);
} else if digits == digits1 {
pandigital1.push(magic);
}
count += 1;
dcount += 1;
}
digit_count.push(dcount);
println!("There are {} magic numbers.\n", count);
println!("The largest magic number is {}.\n", magic);
println!("Magic number count by digits:");
for (i, c) in digit_count.iter().enumerate() {
println!("{}\t{}", i + 1, c);
}
println!("\nMagic numbers that are minimally pandigital in 1-9:");
for m in pandigital1 {
println!("{}", m);
}
println!("\nMagic numbers that are minimally pandigital in 0-9:");
for m in pandigital0 {
println!("{}", m);
}
}</syntaxhighlight>
{{out}}
<pre>
There are 20457 magic numbers.
The largest magic number is 3608528850368400786036725.
Magic number count by digits:
1 10
2 45
3 150
4 375
5 750
6 1200
7 1713
8 2227
9 2492
10 2492
11 2225
12 2041
13 1575
14 1132
15 770
16 571
17 335
18 180
19 90
20 44
21 18
22 12
23 6
24 3
25 1
Magic numbers that are minimally pandigital in 1-9:
381654729
Magic numbers that are minimally pandigital in 0-9:
3816547290
</pre>
=={{header|Wren}}==
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